2003 Nissan Frontier Speaker help

I want to change the original factory speakers which are 2 Ohm 15 Watt, 6 3/4" speakers that have an integrated spacer/molding and use some Pioneer 3-way 6 1/2"  but the problem is that if I mount the pioneer speakers,  there is no longer clearance for the window to roll all the way down and if I use washers to space it enough,  there's too much gap and the speakers sound like crap compared to the original factory speakers.    Is there some sort of adaptor plate or spacer or other solution I can use?

I would say I need about 1/2 inch or so.   I would prefer to do it with something pre-fabbed if there is such a thing.