I've got a 2001 A4 1.8t without the bose sound system. I went to have a pair of 5.25" boston acoustic components installed this weekend and I was told that they were too deep for the space available. If anyone knows what speakers will fit, please let me know.

 

check out http://www.crutchfield.com/. they'll tell you what fits and give you some recommendations.

 

i have polk momo 5.25s and there was more then enough clearance