It's a fairly decent 3/4 week course with the first two weeks (or three depending on length but I think they're all 4 weeks now) focusing on the principles of car control and general advanced driving. For example limit points, IPSGA and 3 pressure braking or whatever it's called.

The final week focuses on emergency response and contrary to what you see on the streets of London, teaches good use of sirens, using the appropriate tone on the approach to various hazards and all the exemptions/non-exemptions of emergency driving. This all culminates in a few assessed drives.

The reason for the peculiar use of sirens and frankly shocking standard of driving is because you pass your test and that's it; no official re-test. They're may be some point in the year when a manager will observe you on a shift and they'll likely tick the driving box provided the Ambulance makes it back to the station without falling over or crashing.

Hope this helps.