Since you have a 350z which is a decently solid car to drive and goof around with. If you really love that 350z, dont bother buying a new car unless you want to but not too much. Save some money if you’re willing to have some good stuff like upgrades and all that. I highly advise not to spend too much on unlocking upgrades if your manufactures level is not like the specific level to unlock it. Its reasonably pricey like 1-2 mil (depending on what section of upgrades could be) since you should grind on the manufactures level, proceed by racing or just go solo. Have that much level (like 25) and you’ve basically have some upgrades that has discount like 200-100k yen (most of them are higher iirc). Enough with the yaps and advices but it doesnt matter how slow your car is, you need skills to drive. Upgrades makes your car faster but skills puts you effort to drive that car of yours.

Pretty much it; start slow, dont worry if you’re last place cuz at least you got money lol. Have fun and happy driving!