Only issue with car stereos is you need to provide a speaker switching box if you want sound in 3 areas. If you play the outside speakers at all then that would be an issue without a switching box. And you can't play DVDs as well. You would need to add a DVD player.
On our last TT the el cheapo Touch Audio stereo went out. I just bought a cheap Sony car stereo. I fab'd a wood plate to fill the hole. Cut out the opening in it for the Sony. Worked great. No outside speakers though. And we did add a DVD player plus a small 3 speaker PC sound system. Worked well for the few times we watch movies.
Totally agree on Jensen being junk. While OEM auto radios aren't always the best they at least usually last a long time.
I see that Outdoor RV puts a Pioneer unit in their trailers. Might be worth a call if you want to maintain the RV speaker setup.
