I saw a 4x4 once with fully finished (powdercoated, machined alloy, and painted) undercarriage, and the underglow served to enhance that. Other than that, underglow? Meh.
SR #265 | "Quia currus certatus, inferius"
13 Focus Ti Sedan w/Handling Pkg, MFT Sony 10 NAV, Leather
13 Focus SE HB Sterling Grey, 201A, Leather
06 F350 6.0L DRW King Ranch, Sunroof, Rhino Bed Liner, 4" MBRP Turbo Back, AirRaid, Edge Chip w/Pyro