Like all Honda's I have owned, the Del Sol is yet another example of the thoughtless engineering of Factory Honda Car Audio. It has been identified that the Del Sol uses a total of four 6.5" speakers, one in each door and two in the rear. The speakers in the back are very shallow and only allows for about 2.5" inches in depth.
I have started looking at the following speakers for the doors:
MB Quart Speaker Kit PVF 216
Kenwood eXcelon KFC X1710