Ah the MX6... I had a 95 MX6 V6.  Was a nice commuter car, never let me down.  Never did any mods to it though.   
As for my MR2... I really enjoy the car and hope to keep it for a long while.  That said, despite the amount of money I've put into giving it a more healthy amount of non-laggy power (V6 turbo helps, original car is a bit lacking), I bet I'll end up replacing it this decade.  With what I don't know... want >400hp, <2300lbs, smaller than the MR2, and MR.