Just FYI, after reading a few threads on this issue I thought I'd tackle it myself.
Ok first of all, buy 6x9 speakers unless you plan on drilling a few mounting holes for 5 1/4.
Next get the bandaids out because after all the tugging and pulling your going to get cut.
May I suggest Bactine! Also Advil for the leg cramps that your going to get from being in that small area. After saying all this, I bought 5 1/4 being short of money and from looking at Crutchfield web site showing what will fit in the back. Bottom line, I installed the speakers in the door and still have to go buy 6x9's. Heading to vegas this Friday and wifey is going to be pissed im spending money on speakers. LOL