You can't stereotype cars in this situation, though. A lot of modern cars will have plastic reflectors / lenses and sticking 130w bulbs in there isn't recommended.
The wiring is also something that can't be judged by brand, either - all manufacturers will get away with using the thinnest / cheapest wire they can.
A reasonable quality head unit and speakers are all that's needed.
Amps won't make the blindest bit of difference, other than making it louder than you need.
OK, but there's absolutely no reason to fill your car with amps and speakers, as it will never sound anywhere near as good as a decent domestic set-up no matter how much you spend on it.