There are several factors that may allow them to register their vehicles in a location different from the physical location of their business. Depending on the company structure (LLC, S-Corp, C-Corp, Sole Prop) they may be able to register their vehicles in the location in which they personally live and still deduct the vehicles for tax purposes. They may have worked out something in their "tax breaks" that allows them to register in a specific city.
I understand your frustration that it seems this company is circumventing the rules
and seemingly getting away with something, but without knowing the "in's and out's" of the company it is hard to tell for sure what, if anything, they are doing wrong.
In some instances, if a business has an office in the home, or as you mentioned, a field office, this would allow for this type of transaction
. A field office need to be nothing more than an address. To my knowledge there is no minimum time requirement that must be met.
I am assuming it is much more expensive to register a vehicle in WV than in VA. While it seems unfair to you, it is difficult to determine whether they are doing something wrong or simply have found a loop-hole.
My sincerest advice to you , as I am assuming this company is your direct competitor, is to be the better person, do the work better, serve your clientèle better and make your business the one people want to deal with. Let them do their thing, if they are doing something wrong, it will catch up to them in the long run, it always does.
I know this answer isn't the one you may have been hoping for, but I do hope you find your mind at ease over this situation. Best of luck to you in your endeavors!