i have not installed any car audio amps on any of my cars ever since my '05 evo viii. however, i have a buddy who has an e90 and he had stackable amps hanging from the trunk. his amps were the alpines and he has had the car for 3 years without issues. i know hanging older generation amps upside is a definite no-no but maybe those allow for it? nice idea for the enclosure though. make sure you take your car with you when shopping for a stroller. i bought my f30 without bringing my son's stroller only to realize that it did not fit when we got home. well barely but we cannot go shopping if we take that stroller with us.
it was a stokke xplory.