All brands can have advantages and disadvantages. well except the top range Rainbow but then I suppose the disadvantage is they cost 6k haha.

What is your budget mate. I think there 17cm for the doors in a MK4.

if you want abit of bass, look at the vibe qb69, there the rectangle 6x9s and bassy, got them in my 6n, with a pair for veolocity 6x9s all in the parcel shelf, but nobody nows that because there sunken and coverd, then put fli 6.5" in the doors and fli 4" in the dash, sounds good and abit of bass too, clear as you like for a budget, cost me less than 200 for the full lot then head unit on top.