Dunno, but they're dirt-cheap & 1 minute to mount.... couldn't hurt. But either you've got quite a leak at the collector-to-exhaust pipes or at the mufflers, or the seal in the back is not touching the decklid. Exhaust mingles with the big air-swirl behind the rear bumper and a smell could be seeping in from that direction, too. FWIW- J Deryke