im confused about dot&mc #ers

I'm fairly certain it must be exactly as your certificate states.

Recommended 2" minimum in a contrasting color from the vehicle. I posted last 8 of VIN because I did intend to enter Colorado and it makes it easier (still got called in first time to show insurance, but after that, never had to stop and show anything).

 

The name on the truck should match the authority. You can use an abbreviated name if that is the way is is on your authority. You can also have a dba instead of the corporate name, but it must also be listed on your authority. I still put my MC number on my trucks. We are now only required to have the DOT number, but I hate to change after so many years. You also need to put your truck number on the truck.