Radio/tape Cd Player problems of the 2015 Toyota 4Runner

Purchased a 2015 in Dec. 2014. . In 2015 (not sure of the first date but know it was when going to granddaughter's soccer game) we took a trip using the navigation system and radio. They system stopped for about 4 seconds and started again but had to reenter the navigation. We asked about it and was told it was like a cell phone that stops in some hot spots. It did not happen a lot at first but each time we were told it was a hot spot. The problem kept getting worse. We inquired and was told service would do a diagnostics on it but a cost. We were not willing to pay over $100 to check the problem. And now it is 2018 and we are checking on the internet seeing that it is not hot spots but a problem with the system. Only our warranty is out as of Dec. 2017. 2 months. . It is a distracting when it goes out while driving so we have to be very careful not to get distracted. We take a map and print outs from google drive to help when it goes out. As per reference number: TSB#5b0035-16. . . Many Toyota vehicles have the same problem. . . We have been in contact with Toyota headquarters. . . #1802282446. . . They will not do anything to help. . . Even though this is an on going problem in their product on several vehicles. Thought Toyota was better than this. . .