Just trade it in. I think the car is too new and still in good shape to swap the whole drivetrain. Not only that, but you still owe money on it. So it might not be completely your car (bank may have title). For the pay off on your car now (16.5k) you could get a 96-98 Cobra. To me, having a V6 (Roush or not) isnt worth 16.5k. But thats just my .02