wats d story lads im new on here..iv a 9n 1.2s, so far iv alloys and de-badged the rear...nothing major

..... yet

!
iv a couple quick questions for any one who knows..!
1) do the 9n3 rear lights fit the 9n??they look the same shape....
2)the electric window on the passenger side has a mind of its own

!when its open and i press the button to put it up,it goes about 3/4's of the way up,stops and then goes all the way down and i cant stop it going down when it does!!then when i press the button for it to go up for the second time it stops about an inch from the top so i must press it a third time before its actually closed!!! this doesn't happen all the time but a few times a week at least!!! any one else ever have this problem???
3)im thinking about a sound system,what would ye recommend? nothing too pricey though lol!!
thanks in advance!!