I only recommend two types of enclosures/set-ups, purely for SQ. It's my personal preference, so keep that in mind.
2. Infinite Baffle (free air)
Both are efficient, produce tight, accurate bass, with a fairly flat frequency response, and do not produce much rattling of the trunk panels.
I have not tried IB in my car, but I know what such a setup is capable of, and it will be my next project.
Mobridge DA2 > JBL MS-8 > ARC XDi 600/4 > JBL Gti 408 Mids & Vifa OT19 Tweeters; PG Ti2 1600.5 > Morel HCW-10 & IDMax 15