This summer I bought a new Bahia, which had an AM/FM/CD player installed as an option (I wasn't looking for this, it was already on the floor model I bought).
Sadly, as I live in a rural area, I could only pick up a few of stations: 1 good country station, a so-so- pop station with poor reception, and a couple each of Tejano and hip-hop stations. As my wife's car is, in effect her office, I decided to give her a satellite radio system (XM Radio, although Sirius is probably just as good). I was so impressed with it, I bought the home system for it, and I thought I would see how it worked out on the deck with the hot tub.
All I can say is WOW! I now can get all kinds of good music to play (with no commercials) on the hot tub stereo, and I didn't even have to run any wiring, just hooked up the XM radio about 6 feet away from the tub. It has a built-in FM modulator, and plays thru the FM radio on the tub's factory stereo from a distance of several feet away. I just thought I would pass this info along, in case anyone else had crappy reception on their spa stereos and wanted an easy way to get better tunes. I had previously tried an FM booster on the spa's antenna, but it had little effect.