Re: 4x10" to 6x9" adapter help
Ha, I had the same problem with my Cutlass Ciera. The easiest thing to do is build a baffle. Make it a little bigger than your 6x9, making sure you have enough clearance to fit some bolts around the edges but have it still fit underneath the hole. Use a router to flush mount the speaker in the baffle, then drill down through the deck and through the baffle. Put some big bolts in there and a lock/flat washer and you're good to go.
"The world is full of people who want nothing short of perfect,
but settle for less, blinded by their quest for purpose."