No fancy paint package called "Premium Sport Edition". No heavier , but still impractical sedan that is likely to fail to get buyers just as IS250 RWD 6-speed didn't sell.
Take the rear seats out. Make a plastic roof that folds down where the rear seat was. Make it a Spyder, a newer, better option than a targa or fabric roof convertible.
Give it a 3.4 Liter EZ34R engine. Don't know what that is??? Here's how to build one.
1 Take EZ36D block with 6 92mm bores.
2 Make new H6 crankshaft with 86mm stroke.
3 Use FA20DIT-style straight, strong con-rods and make new high compression pistons for the 92mm bores.
4 Add Toyota's Valvematic valve lift system to the cylinder heads, which won't make the heads any thicker than they already are, and are more infinitely variable than the two-mode AVLS system that EZ30R used to have.
5 Use Toyota's D-4S compound fuel injection system, or Subaru's direct-injection, whichever works better.
6: assemble and dyno tune to the same 100hp/liter rate as the FA20 FRS/BRZ engine. 340 peak horsepower. With a 7500-8000RPM redline.
7: put it in front of the BRZ's 6MT, with a strong, torsen-equipped rear differential. Maybe tweak the front spring and damping rates just a little. The engine isn't much heavier, and less than 2" longer.
Even if the drivetrain adds a generous estimate of 100lbs, and the body adds another 100 or so (less glass and metal, less interior, but somewhat offset by the mechanism for the trunk lid, and folding roof)
Even if the 2900lb car becomes a 3100lb car.. with 340 horses with more latent torque from a 6-cylinder engine... it will likely be about as fast as a 3200+lb 350hp Nissan Z (faster than the likely heavier roadster), or a 3400+lb 305hp Mustang V6, Genesis V6, and likely significantly quicker than a much heavier Camaro or Challenger V6. Power-to-weight probably closer to the V8 versions of the american muscle cars.