iPod crashing when connected to car

I have a Toyota Corolla 2015 with a usb and headphone jack port to connect music. I connect my iPod classic that I modded using the 30pin to usb. It’s began to crash every other day when connected. Is anyone having this issue. Is there a better way to connect to your car? I have a iflash microusb in my iPod so I don’t wanna damage it with it crashing