yeah dual on both sides. i guess im more on the cosmetic side.. plus im a girl so you know i really like the look.or do you mean dual mufflers on both side? if so, it works. you might have to bang in the wheel weld a bit, but it will work.
weigh wise, i wonder the same. i have dual exhaust setup too and i believe it does weigh down the car since its an extra piping + exhaust than stock. its mainly for looks, not performance.