If you file for individual (not joint) bankruptcy and your spouse's autos are not in your name (and have not been transferred within your state's allotted "look-back" period), they should not be part of the bankruptcy estate because they are not your assets. In that case, you would not list them on your schedules and would not have to claim them as exempt.
This answer is provided for informational purposes only and does not create an attorney-client relationship. A more detailed explanation can be provided if you contact our offices directly.
Your trustee will not be able to reach your husband's separate property, unless the funds used to purchase them were yours, i.e. the auto(s) was a gift to him. In fact you will not be required to disclose his property at all.
Your property is all that the trustee can reach. However, if you transferred your interest in these vehicles, the trustee may be able to reach them that way. If you gave separate assets to your spouse to purchase the vehicle, the trustee may be able those assets. If like many people, you put separate property in separate names, there is nothing to worry about.