I just loaded up my save file from that point in the story (I kept one save before every boss), and I was level 50 at that point while playing on normal, just as a reference point. There are two places in the wasteland you could try out if you haven't, and you can reach both of them at this stage of the game, though you may need tires than can traverse spikes, and a bumper that can destroy boulders. Anyway, I just tried them out myself and here are the results:
Central Wasteland (south) near the Canyon Village. The enemies I fought were level 42, and it took me around 3 fights to go from level 50 to 51.
Southern Dunes (southwest). The enemies I fought were level 27, and it took me around 6~7 fights to go from level 50 to 51.
Maybe there's some faster way to level up though, or maybe you've already beaten Raoh, but I just thought I'd mention this as an option.
I appreciate the feedback. Am at level 32. Buggy can get to where Raoh is, IDK anywhere else. Raoh kept kicking my arse, thus trying to level up to at least 33 or 34. Get something that will help. Right now feel stuck.