E46 M3....fantastic engine and a proper coupe that is robust and you can get all of your family and stuff in the boot too...bit like a Golf then!
Been there too but not for long. They are so different in their delivery. Much less torque @262lbs peak and they rarely make anywhere near the factory 338bhp same as the 321bhp E36 Evo's. Most BMW tuners I've spoken too all say the same. It's a bit like the V8 RS4/R8 engines...few make 414bhp...APS state more like 390's and a full house Milltek, induction and map sees 414bhp
Lovely noise and chassis is sublim but brakes are poo.
Big buck's to mod but I'd skip power upgrade's and go Bilstein/KW chassis together with AP big brakes....proper ring car with Inter's.
Can't really compare directly with a OE Ed30 but a full stage 2 Ed30 will give an M3 a real run for it's money.
Off the mark RWD gives an M3 the edge but the mid range thump of a stage 1 or 2 mapped Ed 30 will give it a clean pair of heals. I thought my Golf as it is now feels so much more alive due to torque and bhp/ton advantage. Mine even sounds as good only because of the exhaust but as John says you need to do your homework buying one especially cheap high milers.
Because of the market at mo nice examples have gone back up!
Servicing costs can be reduced out of main dealer network but you still don't want to skimp and they are in another league cost wise especially Insp 1 and 2's!
Good car but not a great anymore IMO what with everything moving on with technology and chassis advances .
Track prepping one costs a fortune!