Originally Posted by Freon
Intercooler + tune, $800-2000, should put you over crank power of the V8 and lots more torque, still emissions legit in 49 states
LSD $3500 (for a manual)
M3 front control arms, rear subframe bushings, $1200 (ish? I'm not looking this up)
Wheel and tire upgrade $2000-2500
With those upgrades, yeah, a 335i or better yet 135i is really in line with a V8 M3 and easily surpassing an E46 on objective terms. But that stuff all adds up quick! #bmwtax
All of which adds absolutely ZERO value to your car. Best option is always to go with the best car you can afford. If you plan on modding, then your best bet is to put that money into getting a better stock car.
Did bmw mess up by offering the 335i... not at all. It was a great success that targeted two different markets.
I'm not really a fan of forced induction and the 335i reliability scares me. Therefore because I couldn't afford an M3 and a 328i just seemed way too underpowered for me, the g37s was a great alternative.
Different strokes for different folks.