Dear Chevrolet: I am a little disappointed that the 2020 3500 HD w/6.6L Diesel engine that I have on order will not come with what I consider to be a mandatory safety feature! Namely a locking fuel door! Besides leaving the fuel filler accessible to anyone with a finger, the fact that the DEF filler is also located in the same unsecured location is totally unacceptable. Given the havoc that can be wreaked by persons wanting to add damaging fluids to either one of the filler spouts, I just find this Foolish & ridiculous!