Re: Sound deadening
you could use Weather stripping foam tape instead of clay if you can mount it with bolts instead of screws. then you can really damped the MDF and keep a good seal.
I don't thinkt he shape of foam matters much. I used ensolite foam from RAAMAT, it's super thin and is flat but has acoustical properties.
Nissan Titan KC
Eclipse CD7200 MKII HU
DLS Iridium 6.2 Front Stage
Arc Audio XXK 2100 for fronts, Diamond Audio D5 1200.1
Knukonceptz 0 & 4ga and all Speaker wire and Streetwires 0 ga Power/Ground Distro Block, 4.5 rolls 60 mil RAAMAT and Ensolite foam througbhout, Kintetik HC2000 The Big 3 + 0ga Gounding Kit.