The usual way couples handle the division of vehicles in a divorce is that each takes their own vehicle and the debt that is attached to that vehicle.
Start with getting the fair market value of the vehicles. You can find that on the internet at a site such as Kelley Blue Book (www.kbbcom) or NADA (www.NADAGuides.com). Be sure to value all vehicles in the same manner. Either both at trade-in or both at private sale prices. I prefer the latter.
There can be some minor complications with vehicles.
Vehicle driven by a minor. In this case, one of the parents will need to keep this vehicle titled in their name. Hopefully, the couple can come to an agreement about this. Be sure to consider that the titled owner will need to have auto insurance on the vehicle.
Vintage vehicle in the garage. Sometimes one cannot find a fair market value of a vintage vehicle because it is not truly vintage. In this case, the couple is wise to come to an arbitrary agreed upon value, allocate the vehicle to one party and move on with other decisions.
Vehicles with interesting debt. Once in a while, a couple will finance an vehicle through a second mortgage on the home. This can get sticky when one party intends to keep the vehicle and the other party intends to keep the home. In this situation, the couple needs to look for an offsetting asset. The party keeping the home (and the vehicle debt) would get an asset to offset the amount of the debt. Presumably, that party could cash out the asset and pay of the vehicle portion of the second mortgage.