As I explained in the first installment of this series, Audi markets souped-up versions of its cars with the S designation. So what is the RS4? RS is like S, but more so. The analogy is old and tired, but if these cars are A4s on steroids, then the S4 is Jose Canseco and the RS4 is Barry Bonds.
Things are more confusing than ever, unfortunately, because Audi now has "S Line" option packages that give A4s suspension upgrades and the appearance of an S car without the muscle to back it up. False advertising, if you ask me. The S and RS are real players; the S Line is the tailgating fan who's not on the juice so much as the sauce.
The only RS model sold in the U.S., the RS4 ($66,000 base, $73,520 as equipped) looks like an S4, but the only sheet metal it shares are the front doors and the roof. The body is wider, with more prominent wheel arches, and the nose is different.