From personal experience and from issues others have had, I would not get an E46. As was mentioned, took some bucks to get rid of the rasp, but that is only a rasp terminator pipe and cat back, so not too big a deal. But reliability is a different story. I haven't had my E92 long enough, but the reported issues are few. Much fewer than the early days of the E46. At this point, saving money with a higher mileage E92 seems a better shot than getting an old E46. Even with the 6, the E46 was a "heavy" car. Now, an E36 would be an entertaining little car. But now your talking a car with 100k miles and that is a whole different ball game. BTW, issues with my E46 were VERY expensive. Keep in mind that the 40k or 50k dealer service is like $1500. Much cheaper to own a 997!
E92 M3 MR on Red/Black ZCP Sound
2007 997S - sold
2003 E46 M3 Steel Grey on Red- sold
1997 E36 M3 Arctic Silver on Black- sold