6.25" same as front. JBL do some at that exact size, but I got some 6.5" (17cm) to fit in by drilling one extra hole through the metal of the parcel shelf. You need to take the rear seats out and then you can get that carpeted board shelf out with a bit of tugging and slight bending. Easy enough from there on
Cheers, i presume theres no problem with mounting depth, looking at the range from theloudest.com, had his 1000w in the back of my celica and they were awesome, don't think he does 6.25" though.
I bought the 17cm (6.5") from "the loudest" actually... just an extra hole needed to be drilled, but for a more professional fit you might need to do two... I was just lazy :lol: