Sorry but 6.5s will fit around in P5s. I've got them in the front. Now depth might be a problem with some but 6.5 polk fit with no trouble.

 

Pwn3D Miller!!!

 

Indeed. Was mounting not a problem? You didnt have to drill holes or anything?

 

I forgot about the P5 having that awful rear door speaker location. Just what ya need, a smaller rear speaker firing right into the front seatback sides.

 

ACK!!!

okay firstoff, stock speaker sizes for all 3rd gens are as follows:
front 5x7 (same thing as 6x8) Many ppl build baffles that are basically an oval with around hole so taht you cna fit a 6.5 mostly because most really ncie speakers don't come in 6x8.
rear doors: (both sedans and 5's have holes for them) 6" YOu CAN fit a 6.5 if you trim back your front "splash guard" however 5.25's fit without trimming plastic.
reardeck: 6x9 (but it's dumb to buy an expensive speaker to put there)

Nowthen. as far as the factory paper cone ligthweight speakers. it's not a matter of lowest bidder, it's a matter of efficency. Think of a speaker as a weight, and your hu's amp as a muscle. Smaller muscle, you want less weight to move around. NOwthen YES it is good to have hbeefier speakers, but the benefits outside of the added response from an actual tweeter are generally negated by Lack of power.

If you REALLY want your car to sound better, get good front speakers and amp them.

 

and Smaller rear speakers firing into your seatbacks is good and here's why:
you're not SUPPOSED To hear them... yet they still provide decent "fill" or ambient sound as well as decent listening for rear-seat passengers as opposed to a gawdaweful 6x9 barking at the back of their head.