I've had a few of these now and pound for pound they are the best car in that price bracket. BUT they are FUCKING hard work to sell

I've got one of the last Celica GT4s [UK spec and standard, pretty rare now] that's in your budget. They're not bad? Pig dog slow though compared to the skylines.

And I wouldn't toucha £4k M3 personally, may as well buy one for £7k and at least have a nice one, than spend £3k on top of your budget fixing up what will always be a high mileage car.