RLSH700

The other mind boggling thing is you have to take into account the base level prices of these two cars in order to get a real idea what you are comparing against each other. The normal Mustang GT costs around $27K while the base level STi is about $35K. They are comparing a car that has about $8K more into the overall package, although the Shelby adds the better suspension and interior, you could take the wiser approach of getting that better suspension without the collector's Shelby package (which I believe is optional and if not you can buy one aftermarket) for a much lower price. The interior issue is not that relevant as this is comparing performance cars.

The other thing you have to take into account is that the Subaru has already received forced-air induction, even though further mods can be done to this, the Mustang has more untapped potential that can be utilized. For the $8k difference you could supercharge the GT, improve the suspension, and make other changes while having a heritage muscle car instead of a super fast stationwagon. I'd take the Mustang GT anyday over the STi (especially since I could get one at a discount if I wanted to).