i know you dont wanna hear this but your best bet is the trunk. Either that or up under the dash somewhere. There's definately not a ton of space in the doors and those crossovers look pretty big.

'99 SilFro SE V6 MTX Alpine CDA-9833, 12" L7, Pioneer 6x8's, Fidanza Short Throw, K&N Drop-In, Spec1 Clutch/Flywheel, WR Headers / Y-Pipe, TBz Cat, PRT Roll Resistors Mods in queue: Trubendz Res. Magnaflow Ex. SVT UIM/LIM/Opt.TB