Typical issues are with power draw for the headlight motors, ignition system and cooling system. There is a company called Pantera Electronics in Pennsylvania that sells a lot of quality upgrades though, like conversion to a standard fuse box with LED lighting (green and red) to denote failures. Motor controllers for ignition and cooling that control power loading better. And there is a parking brake kit that uses Tesla calipers (the hydraulic parking brake system sucks and loses pressure after a few hours). I will likely be doing a lot of the PE upgrades over the winter.