Well i have tried high pressure sodium lamps or metal halide, The light isn't natural but gives you plenty of area to work with.
every bump, seam, chip, scratch shows up under these light i have found their bloody power full and rather economical to run ..
The only down turns when using these lights they are very heavy due to the transformer and large area reflectors make them hard to move around..
Four lights positioned around the vehicle should give a fast and overall lightened area for washing and drying .
Be careful with temporary lighting when using extension leads, make sure there is a safety device connected to you leads to minimize the risk of electrocution,
keep all leads raised from the ground.
better than that have some lights installed on post around the area in which you designate your wash zone . to easy very convenient if you cant get home early enough and wash during the evening..
try blind folding your self and then wash your car, rinse and dry see how you did no needs for light :lol: