Agree with posts...your dealer should be helping you.
Each state can be different. We've had no problem registering Backdrafts for our customers as 65s in Michigan. But again I know the right coast is different.
As an alternative, and that is to register in Montana under an LLC. Very common process. Simply, an LLC is setup, your Cobra is registered in the LLC, Montana law is applied, insurance is sourced in Montana.
This is all managed for you through Deer Creek Corporate Services
https://www.mtvehicles.com/
Hope this helps!
Jeff
Jeff@nostalgicmotoring.com | 586.489.5990