Antilag won't make your car sound like an impreza... We have an inline 4 not a flat 4 engine.
Proper antilag won't be useable on public roads, my uncle drives around and it I can hear him before he comes near our town, if you ever heard gunfire up close that is basically how bad it is, constantly, it's enough that it sounds like a jet engine with the twin wastegates opening through full titanium exhaust but to have the gunfire pops it really isn't useable...