I've been inside a few different versions of the M3 and I'll admit they are SWEET ass cars..but sometimes I think it's a bit better to be more 'creative' and break away from the crowd...though if your 'crowd' has cars like the M3, you're in a pretty good crowd.
But, I've been a HUGE fan of the 300zx for Years...and speaking of 'being different'...I found this "Z" on the net recently and will have to say that I think this car would get more pussy then anyone driving a Viper...
http://user.tninet.se/~bjx414c/newjacke7.jpg
as for bying a used Viper and adding $4k worth of upgrades, I'd like to know..really...what mods you'd be needing to get...