Golf carts are a blast to play with. We have our shop gas one here for promotions but essentially my daughter and I just blast around the abandoned subdivision developments in it. Kinda ashamed of the stereo as of yet though. The last owner popped in the $19 Dual HU (at least it is mounted securely) and some KVH boxed house speakers in the cubby holes. I have to say though, it gets really loud! Ours has a 6 inch lift, 22" tires, custom paint (seat hasn't been "gatored" yet), and some engine mods. Trying to get time to work on it is the problem.
We have a large golf cart sales place less than a block away that customizes them. I have seen some crazy money put into them. And, Luke here worked at a shop that did a crazy one for the Bucs complete with fiberglass roof, amps, HU, etc. We later added bluetooth since Verizon sponsored it and it is pretty badass. I have pics somewhere that I'll post later-maybe give you some ideas!