Another thing to add is the effect lowering the car has in an accident.
Just something to be aware of.
I know my bumper would have little to no effect if I were to hit a SUV or even a compact car with a high stance like a Matrix or Cavalier. And side on would be even worse other car would hit well above my doors crash bar.
The major difference between my 318is and an e30 M3 is that the noises come from the engine and not the passengers