I just had a quick thought. Instead of cutting wires etc. or going to the expense of buying the R-Spec Japanese kit by Data Systems; why not locate the wires that hook up to the parking brake sensor (and dash warning light) and drop a manual on/off switch in that circuit? I had read somewhere that if you just barely set the parking brake while driving, just enough to turn the dash light on (of course, I would not recommend this) , it sends a false signal to the nav system and it works the same as if you are stopped. I would only guess that the motion sensor could not be fooled by this simple little hack or someone would have tried it by now. If I had known the nav sys would not work while you were driving, I would not have bought my new GS350.

 

I completely agree. It is the biggest pain in the a$$ to not be able to use the NAV (which by the way is not user friendly) while driving. I looked everywhere for my GS350 that had to have NAV to be so disappointed. I would love to know the cheat to have this fixed. The seatbelt bell is a real treat as well....