Well you should have the 5 inch backing plate with your PC. Did you get that or do you just have that big white foam pad that came with it? If you don't have the backing plate, I highly recommend that. Use that and you can use 5.5 and 6.5 inch pads. In all honesty, they are big enough to do large panels but still small enough to manage some more delicate areas. I used it on my hood with no problems around the dome. The vents I taped off around the edges with painters tape and once I was done with the PC I did the smaller areas by hand. You could always just use an applicator and polish by hand too. Of course it takes a bit more work, but it is doable.
'11 BMW E92 ///M3 - ZCP and DCT
'15 Ford F-250 - Lariat, 6.7 Powerstroke Turbo-diesel