[Alpine TSi]

Infinity in 2G's should be centrally amped under the seat, not on the individual speakers. Infinity does make a system like that, but is only used in the newer vans, trucks and such.

And in 1G's, I have done so many and you can almost never anticipate what is in there. You can fit a shallow 6x9 in the rear, or most any 6 1/2 with an appropriate mounting plate. For the fronts it is either 5 1/4 or 6 1/2, it just depends. Most Eclipse'ss were 6 1/2, where most Talon's are 5 1/4. Just hork your door off and see.