If you want an affordable and tunable mid-engine sports car, well, your only real option is the SW20 Toyota MR2 Turbo. The key detail about the SW20 is the "Turbo" part, because it is the 2.0 ...
Why the SW20 MR2 Turbo? Well ... generation took a steep departure from its predecessor by removing the turbo engine in exchange for the lowest curb weight of any MR2 generation, a measly 2,195 ...