I know the rear door speakers are 5 1/4" with a depth of 3 1/2". What is the maximum that will fit without alot of hassle? I am looking at a pair of 6 1/2" not sure on the depth yet. This is the only size I can find from Cerwin Vega in a component system that I want. Fronts are 6X9 and 5 1/4" depth, not too worried about that I can find that size all day.