Property issue

We were separated nearly a year ago, but we still have not separated assets yet. If the ex has made a rather large purchase such as a vehicle, is that included among his assets when we are tallying up assets at the time the divorce is finalized?

No, any asset/ or debt that is incurred after the date of separation is separate property.

If however your spouse used martial money to purchase the vehicle, the amount of funds diverted from the marital estate will be accounted for in distribution.