[kman10587]

Go with the M3. The Boxster is Toyota's rendition of a Porsche, and it didn't turn out very well. The only other car I'd strongly recommend (and it already has been) is the Corvette Z06. It'll definitely be faster than an E46 M3, and cheaper too, but not nearly as luxurious or refined.

However, the M3 and the Corvette were both designed for performance on the track (although the M3 is certainly fun to slide around). If you just want a drift car and nothing more, I'd recommend buying a 95-98 Nissan 240SX or a 93-95 Mazda RX-7 Twin Turbo and tuning them extensively; $40 grand into either one would create a drift monster.