2018 duramax

Does anyone know where I can find mirror caps for the truck above with the temp sensor hole in the cap already? Can’t seem to find any that have it with it.

I was supposed to leave for a trip across country with our fifth wheel tomorrow morning I took our truck in to have it serviced as we are going to put on about 5000 miles round trip. The day before I took it in the check engine light came on for a couple hours then went off the dealer called me...