I had my eye on the Yamaha THR10C for a while and found one at a discount, so I splurged. I haven't played any of my bigger amps since I got it a week ago. Get the one that fits your musical style - original THR10 for maximum versatility, THR10C for sweet breakup, THR10X for more aggressive gain. You won't regret it.

The amp has AUXILIARY volume knob for use as a music system.

If bluetooth is really a deal-breaker, couldn't you use something like this (or its more versatile big brother)?

http://www.amazon.com/gp/aw/d/B00MJMV0GU/ref=mp_s_a_1_1?qid=1415826601&sr=8-1&pi=SY200_QL40

i use this at home to play wirelessly thru the home stereo. its very small and compact and the connection is very stable for 20$. im not sure how the connection would hold up while carving down the slopes but im willing to bet itd work out fine. and if it doesnt then you got a reciever for the car or home