Just a thought, but www.superbrightleds.com has some under car LED kits that may work.
LED Under Car Kit
Kit includes two 48 inch (48 LED) Tubes, two 36 inch (24 LED) Tubes, Mounting Kit with power switch
Select LED color
Additional shipping charges may apply for 2-Day or OverNight shipping
professional installation suggested
I purchased a set to illuminate my truck bed since I put a fiberglass lid on it. You can get them in various colors, or in white which is what I bought. They can be installed up under the rails out of the way, came with mounting brackets. The specific part is here: