Four doors?

Hello all! Well I just sold my jeep srt 8 and am looking for my next ride. I have been beating around a few ideas but need some advise. The five cars I am looking at are the e46 m3, e90-93 m3, e60 m5, e55amg or e63amg. I know I am on the wrong forum for the last two but those are my interests, overall I am not brand savy, I just enjoy a well engineered fast ride. What I need are four doors, was it even an option for the e46 m3? My other requirement is that it launch as fast or faster than the Jeep out of the whole. My big restraint is that it has to be under $50 g's. I have been doing alot of looking around and it seems you can pick up a 2006-2008 m5 for around 35-45 g's. But how much are the mods going to cost? And which mods will not void any warranty I get?? I need a warranty and reliability. Can that be achieved with any of these model that I listed? Any suggestions will be greatly appreciated and if any body is selling one of these rides drop me a pm. Thanks Rob

four doors was not an option for the e46 m3 but it is for the e90 and 93, idk about the e55amg but i have an e63 amg and its two doors. if you are going to mod the best choice is definitely the e90-93 m3, there are tons of mod options out there, as far as warranty, i know dinan, vorsteiner, turner motorsport, and ing parts do not void your warranty, mod cost is definitely lowest for the m3's mainly because with the e60 m5 you are dealing with a v10 and that tacks on cost like you wouldent beleive. acceleration wise the m5 is a bit faster stock (4.3 0-60) than the m3 (4.5) but once you upgrade the m3 it will blow the socks off the m5. you can get great upgrade turbo kits anywhere from 13000 to 44000 which will put the m3 at about 520 hp, for power purposes basically making it a v10. mine has a kit for 15000 and gets 520 hp and 0-60 is 3.1 s 0-100 is 7 s, but unless you are racing this gets a little ridiculous daily driver, given that cops eyeball an m3 a mile away even when going the speed limit!!