Get some fibreglass and make some!
It's not that hard, I've done some for my Sei (check my gallery), look a bit cack in carpet (God knows what I was thinking when I did it!) but I've started to trim them in vinyl and they look a million times better and almost factory. The fibreglass is expensive to buy though.
I went for 5.25" comps but 6.5" would fit just as well.
There's a place in Italy that make some, J333EVO was planning a group buy a while ago.