I only used Mastic on the outer door skin interior, and then I sprayed over that and the inner door skin with this stuff called Cascade VB-2 spray - like spray dynamat.
I covered the wires with aluminum foil and then when the spray dried I pulled it off wink

you can get the spray for $20 from parts-express.com
enjoy.

'98 Tropic Green Tour SE Sport V-6 ATX
"I promise I wont modify it honey, it's a family car!"