Was in Tractor Supply yesterday and found the perfect LEDs for the tail lights. They are submersible boat trailer lights, but when you take off the lens there is the led plate that fits perfectly in the motorhome tail lights. It is only screwed in and comes right out. It also includes the white license plate illumination lights which I removed to use elsewhere. They cost $18.95 each, but you can buy a pair cheaper.
http://www.mytscstore.com/detail.asp...productID=8858 