anyone else have problems with there mark levinson sound system
sometimes i will be driving and all speakers stop working except for the front dash ones. i have to turn off the car and start again and then they work again

 

IDK but I haven't heard of the amp going bad and only passing signal to half a channel unless the dash is not connected to the amp and only doors/rear are?

 

sounds like the amp is overheating and going into safe mode / disabling channels or shutting down all together. Common causes for this are a weak battery starving it of voltage, a loose or bad ground (unlikely if still stock install) & the amp beginning the end of its life (most likely). It will get worse, not better. Good luck with things

 

What car battery are you using? Specs on the car battery?

 

I had a similar issue, but all speakers cut off a few times. Fast forward about 6 months and my mechanic disconnected my battery to get to my last spark plug. The radio/nav system totally bricked when he restarted the car. Brought it to the Lexus dealership and they confirmed the radio/nav was dead. Lexus replaced it outside of warranty.