Just because a business card was used to pay for the car doesn't necessarily make the car a business asset. Indeed, if there was no business use of the car at all it expressly isn't a business asset. If the car was only ever used by the wife for ferrying kids about and going shopping it has nothing to do with the business and the running costs of it shouldn't be going through the business (which doesn't necessarily mean that they are not of course but that's a whole different can of worms).
The issue here is firstly who actually does OWN the car and secondly, if it is either dimjp or his business, how do they get it back. The latter would presumably require solicitors and potentially bailiffs eventually if she doesn't co-operate willingly. The former is a matter for debate. Does the wife believe she was "given" the car? Is it matrimonial property? Etc. There's insufficient info here to know.