You can quite simply drop a quality-burned chip in the S4, along with better intake and exhaust, and you're sitting around 320-350HP with these monsters. Drop in bigger intercoolers, mmmmmm, 380HP. Bigger turbo's and a reburned chip, ooooooooo, 400-430HP.
I've seen some dyno's putting certain chip's alone at 40+HP (some problems with boost spiking, though, which can COOK a turbo).
Don't EVEN go there with the RS4. I'd barter my soul for one of those. With a few more mods, some more boost...
The looks you'd get after demolishing Porsches, Corvettes, Vipers in a 4-door grocery-getting station wagon (shooting brake for those across the pond) would just be too much fun.
