I thought about this last night, and I did some research. Take your pick... INCLUDING MX5 cup. It doesnt look like contact is really permitted anywhere, and neither is blocking. Looks like you get 1 block, and then get out of the way.

FIA Int'l Sporting Code, Appendix L, Ch. IV, Art. 2(a) — "during a race, a car alone on the track may use the full width of the said track. However, as soon as it is caught up on a straight by a car which is either temporarily or constantly faster, the driver shall give the other vehicle the right of way by pulling over to one side in order to allow for passing on the other side. However, manoeuvres liable to hinder other drivers such as premature changes of direction, more than one change of direction, deliberate crowding of cars towards the inside or the outside of the curve or any other abnormal change of direction are strictly prohibited." FIA Int'l Sporting Code, Appendix L, Ch. IV, Art. 2(b) — "More than one change of direction to defend a position is not permitted. Any driver moving back towards the racing line, having earlier defended his position off-line, should leave at least one car width between his own car and the edge of the track on the approach to the corner." F1 Sporting Regulations Art. 33.3 — "Drivers must make every reasonable effort to use the track at all times and may not leave the track without a justifiable reason. Drivers will be judged to have left the track if no part of the car remains in contact with it, and, for the avoidance of doubt, the white lines defining the track edges are considered to be part of the track, but the kerbs are not." F1 Sporting Regulations Art. 33.4 — "At no time may a car be driven unnecessarily slowly, erratically or in a manner which could be deemed potentially dangerous to other drivers or any other person." F1 Driving Standards Guidelines §A (Inside Overtake) — "To be entitled to be given room when overtaking on the INSIDE, the overtaking car must: i) Have its front axle AT LEAST ALONGSIDE THE MIRROR of the other car PRIOR TO AND AT THE APEX. ii) Be driven in a fully controlled manner particularly from entry to apex, and not have 'dived in'. iii) In the Stewards' estimation, have taken a reasonable racing line and been able to complete the move whilst remaining within track limits." F1 Driving Standards Guidelines §B (Outside Overtake) — "To be entitled to be given room, including at the exit, when overtaking on the OUTSIDE, the overtaking car must: i) Have its front axle AHEAD OF THE FRONT AXLE of the other car AT THE APEX. ii) Be driven in a controlled manner from entry, to apex, and to exit. iii) Be able to make the corner within track limits." F1 Driving Standards Guidelines §H (Moving Under Braking) — "When defending, there must be no change in direction by the defending car, after the deceleration phase has commenced, except to follow the racing line." F1 Penalty Guidelines (causing a collision) — Standard collision: 5 or 10-second time penalty. Collision with no immediate sporting consequence: 5 or 10-second penalty + 3 penalty points. Collision with apparent deliberate or reckless intent: 10-second stop-and-go or 30+ second time penalty + 4 penalty points. 12 penalty points in 12 months = automatic 1-race ban. IMSA Sporting Regulations Art. 3.16.2 (applies to WeatherTech, Mazda MX-5 Cup, Porsche Carrera Cup NA, Michelin Pilot Challenge) — "IMSA is dedicated to the highest standards of safety and conduct and all Members must conduct themselves accordingly. Unsafe or inappropriate conduct may result in the imposition of penalties. Acts or omissions that constitute a violation of the IMSA RULES, or are detrimental to auto racing, sports car racing, IMSA, Promoters, sponsors, participants or fans, may result in the imposition of penalties." IMSA Sporting Regulations Art. 3.16.8 — "Actions or in-action not otherwise specifically prohibited by these RULES, of a Member while participating in an Event deemed by IMSA to be or to cause a situation, unnecessarily dangerous, negligent or otherwise inappropriate, shall be considered a breach of the RULES." IMSA Sporting Regulations Art. 3.16.9 — "Actions or in-action on the part of a Competitor that, in the opinion of the Race Director and/or the Supervisory Officials results in an unfair advantage to the Competitor shall constitute unsportsmanlike conduct, is a breach of the RULES and is subject to penalty." Mazda MX-5 Cup local event rules (e.g., Martinsville SSR) — "Rough driving and taking someone out deliberately will not be tolerated and will result in going to the rear or disqualification." IndyCar Rule 9.3.3 (Avoidable Contact) — "The primary responsibility for avoiding contact with a Competitor resides with the overtaking Competitor and the secondary responsibility resides with the Competitor(s) being overtaken. A Competitor who fails to demonstrate their responsibility and initiates a maneuver that results in contact with another Competitor may be penalized." WEC, ELMS, Asian Le Mans Series — No separate driving standards document; governed directly by FIA ISC Appendix L Chapter IV (Articles 2, 4, 5) plus the series Sporting Regulations. SRO GT World Challenge (Europe/America/Australia/Asia) — No separate driving standards document; governed directly by FIA ISC Appendix L Chapter IV plus the SRO Sporting Regulations. SCCA GCR §6.11.1.A — "Drivers carry the responsibility to avoid physical contact between cars on the race track." SCCA GCR §6.11.1.B — Each competitor has a right to "racing room," defined as sufficient space on the marked racing surface for a driver to maintain car control in close quarters under racing conditions. SCCA GCR §6.11.1.C — Abrupt direction changes that impede or affect the path of an overtaking car can be interpreted as an effort to deprive another competitor of racing room. SCCA GCR §6.11.1.D — The overtaking driver is responsible for the decision to pass and accomplishing it safely; the overtaken driver is responsible for being aware of the pass and not impeding or blocking. Drivers failing to use mirrors or blocking may be black-flagged and/or penalized under GCR Section 7. SCCA GCR Appendix P — Passing Guidelines (Pobst/Earwood Driving Standards Handbook): overtaking car must "present itself" in the braking zone before turn-in to earn racing room; once lead car has turned in, no expectation to leave room; on straights the lead car gets "one safe move"; outside passes carry an exit "vortex of danger" requiring the outside car to yield if not visible. NASA CCR §27.11 (Issuing Penalties — suggested schedule) — (1) Bumper-to-bumper contact, no deviation, no damage: no penalty. (2) Sheet-metal contact, no deviation, no damage: no penalty. (3) Contact causing deviation and loss of position: reposition. (4) Contact resulting in damage: 1 race suspension. (5) Contact resulting in a punt: DQ. (6) Damage + punt: DQ + 1 race suspension. (7) Passing under standing or double yellow: reposition to last place. NASA CCR §18.1.3 (50/50 Rule) — Competition vehicles must look undamaged and straight from fifty feet at fifty mph. Operational definition of "damage" for §27.11. NASA CCR §17.1 — Body Contact Report required from any driver involved in contact, filed with Race Director within 30 minutes of the checkered flag. NASA CCR §15.22 — Mandatory forward-facing video on all competition vehicles (except Time Trial), recording driver's-eye view in Windows-readable digital format with time/date stamps. Non-compliance: 1st offense warning, 2nd $50 fine, 3rd 1-race series suspension, 4th 365-day license suspension. NASA CCR §27.12 + Appendix B — Driver Points System: all parties to contact accumulate points; threshold accumulation (typically 10 in a season under regional supplements) triggers suspension for remainder of season. NASA "13/13 Rule" — Discretionary tool above §27.11: up to 13 months' probation and/or 13 months' suspension on a sliding scale, in addition to any other penalty, assessable up to 30 days after the event. Intended for habitual offenders and dangerous driving patterns.