Is it legal for the company to suddenly require an employee to obtain a "better-looking" vehicle in order to let them have a different position? Or, should the company have to offer a "company vehicle" if it's that important to them?

My husband is going to be moving to a different position within his company (branch sales to outside sales). He will be travelling to visit customers. He has already started doing some of it. He was originally promised a company vehicle... soon. Now, the boss is backing out on the company vehicle. The boss has made several comments regarding the age, appearance (due to age), style (small truck) of my husband's vehicle. It is a 1990 pick up. We own all of our vehicles & don't want to get into further debt, by getting another. I know that appearance says a lot about a company. My husband stays well groomed & well dressed. He is always helpful & has a good attitude. He already has a good relationship with his current (and most future) customers. My husband tells me not to worry about it. I am curious about the legality of the issue.

My question is: Is it legal for the company to suddenly require him to obtain a "better-looking" vehicle in order to let him have the position? Or, should the company have to offer a "company vehicle", if it's that important to them?