I am certain that most CG do not allow you to work on your rig as a result of the mess some would leave behind. Once again, a lot of good folks paying the price for the deeds of a few bad ones.
When I got to the milage where a oil change was due, I was not near a large metropolitan area. I asked the CG staff where to get the job done, reply; ",Uh I'm not sure". So I called a guy in the area who did mobil RV repair, same answer. Called a truck shop 20 mi away, "We can get you in in about a week".
Frustrating when I know I can do the job quickly without making a mess or disturbing anyone.
Disposable Oil drain pan $9
6' x 8' tarp $3
Filter. $5
Oil. $30 (8 qts includes 2 spare qts to add down the road as needed)
Oil disposal at Walmart.