Thanks for all the great input, guys.
As far as modding the S2000... well... a long time ago, I'd modified another Honda product, enough to = the MSRP of the car! I promised myself I wouldn't do that again. It IS a very slippery slope. It's also one of the reasons why I bought the S2000 in the first place--track days, hitting up the twisties, etc. -- all bone stock. I let myself get a few basic bits--baffled oil pan, stainless lines, and most recently, a set of R-comps for the track. But I'm getting to the point where lap times are really consistent (<1 sec/lap) so I'm starting to feel that the car's limited in its current form. And that requires coilovers. And non-staggered wheels. Then new stabilizer bars. Then an ECU reflash. Then new control arms... And if I'm already being a little whiny kid about daily drivability... well shoot... forget about it!
That's the beauty of the M3, at least on paper. Just get in it and drive. Have a little set aside for stuff that'll break (I keep on reading about the throttle gear thing). Fuel the thirsty pig. And just drive. I'm at the point in my life where fun $ (after setting aside for the requisite financial instruments in investments, etc) is spent on upgrades to the house and entertaining guests. And while I used to love wrenching, swapping parts and even entire powertrains, the more time I can spend driving versus wrenching--I'm just that much happier!
With that said, still entertaining the idea of a DD. I hear what you guys are saying about a gently pre-loved Honda CRV or something, but I just can't fathom something that gutless. As such, I started checking out new, base 4dr VW GTIs in 6-speed. Looks like VW has shut down production for the GTI, given the new Mk7 Golfs are gearing up for production. This car is great though. DEFINITELY worried about the mod bug w/ the VW though.
As far as my buddy w/ the M3... still waiting to hear from him. Starting to get the feeling that he might not want to part with his baby after all!