Yes, certainly have. My dealer swapped out my Mk4 Navicomp under warranty as it was thought the fan was u/s.

My symptoms were slightly different - failure to recognise the map, continual rebooting etc. When I ejected the DVD, it was roasting hot.

However, since the replacement was fitted, I haven't had the car left out in the sun for long periods even though we've had temperatures here in the mid to late 30's