I have added lights to both my Maxes. The easiest and cheapest way is to buy the Model 19 trailer marker light. It is available in different color lens. I bought mine from the eBay seller "shotofgas" but there are many vendors. It cost $4.44 plus 1.80 shipping for TWO of them. Extremely easy to install and fits as though it were made for the Max. The first I installed as a running light and my current one is installed as an additional brake light.
Also need to buy the brackets. Shotofgas sells a package of two for about the same price. Can buy two sets for about $12 shipped. They have gone up a little since I bought them. If you split with a friend, it only costs about $6.