I bought an aftermarket carpet from
www.autoupholsterykits.com awhile back for my 4dr Camry. It was a pain in the *** cutting out all the holes for the seats to bolt down, vents, seatbelts and everything else.
You can make the carpet work in the Solara b/c I remember a member on the forum doing it here awhile back with the aftermarket Camry carpet, you'll just have to cut a lil more here and there.
The carpet will form to the Solara when you leave it in overnight and let it sit. I wouldn't suggest taking a heat gun to it but sitting in the sun works good.
Heres a few pics of how the carpet looks.
Hope my 2 cents helps you out.