Hi guys this is my first post so take it easy lol. I just bought a 1.6 16v sport mk4 3dr. I've been reading posts for the last couple of days and now i'm sure i'm gonna upgrade my ICE. I've got a decent HU and now moving on to the nitty gritty. Are the std speakers in the door 13cm? also is there different sizes of tweeter or are they all one size? Also is it best to run these off an amp or is the HU ok? There will be a sub and amp going in too (but undecided any ideas?). All links for stuff is below. Help and advice will be much appreciated.