Campers are typically considered “cargo” on your truck and you can insure them as such. For our policy, we had to carry an auto policy on our truck (including damage to the camper when on the truck) but we also had to carry a renter’s policy to cover the contents of our camper. You can get great RV insurance options through GoodSam, as they are in the business of understanding the nature of RVs moreso than the standard auto insurer. However, most of the major auto insurers will work with you once you help them understand what a slide-in truck camper is.