I do indeed sometimes have dreams of building an exotic 944, carbon fiber tub, and under body aero developed to work well with the '944's shape. The shape of the 944 would be left alone as much as possible.
A light weight compact tranny in front of the rear axel would allow for a lower fuel tank, and deeper trunk space. Light weight 4cylinder built to breathe well at high RPM's. Normally aspirated preferred.
Light weight torsion tube, light weight CF torque tube, suspension, etc.
The major body change I might allow, is a "cut" roof profile. Perhaps a different spoiler or rear wing.
Personally, I like the 80's looking rubber spoiler on the '44.
Interior would be a leaner looking version of the early car, with a hooded instrument cluster. The plastic hunk of a center console on top of the torque tube tunnel would be done away with for a much more organic CF unit. AC vents would also not be as "clunky".
Of course, what gets done to it changes a lot, some times I make a V8 for it, sometimes a compact "W" engine, Turbo, non Turbo, wide fenders, stock fenders. Just dreaming really. Because dreaming can get carried away, engine parts somtimes leave the realm of the practical, and get made out of unobtanium allowing for 15,000RPM redlines.
Would I ever do it? No way, I did 3d modeling for computer games as a teen, and taking a design from my head, into the real world, doesn't work for me. In the real world, I work by evolution, start with a block, no idea what its going to be, and just keep working on it. In this respect, I love legos.