u should have posted this in the general section. but with a rf 1500.bd i'd do a single 18 or dual 18's in a tahoe. i'd get 2 OA 18s, or 2 ssa ICON 18s. that would be night and day difference from the L3 on 500watt.
C-pillar flat wall best score: 158.6db
1 vital power 700.1 @ .33ohm
4 NSV3 18s
8 pwx crescendo 10s
Quad excessive amperage 350alts
4 juicebox 3100s