Unless you agreed in writing to assume your wife’s pre-marital debts you bear no personal liability to those creditors.
As far as the truck is concerned, I’m first going to assume that there is no equity that would be available to any of her attaching creditors.
Secondly since the truck was purchased during the marriage it is presumed (in California) to be community property regardless of whose name is on the title.
Hopefully she won’t quarrel over the truck and will agree to transferring it to over to you on the condition that you assume the balance of the lien.
If not, then you’ll have to ask the family court to award it to you subject to the lien.
If it is your personal and/or business means of transportation, there should be no problem there.
However, inasmuch as the truck title was taken in her sole name and should she not voluntarily do so, then you need to see to it that the divorce decree orders her to promptly execute and deliver to you such documents as California DMV requires in order to effect the transfer of ownership.
[Incidentally, just how sane was she “b-4”? Like 6 months ago. And how much sanity does one possess in choosing to tie the knot with someone a "million bucks" in debt? Lol.]
I'm not sure it's going to be that easy. Even if there's no equity on paper, the creditors may not be happy with her shedding ANY assets.
Since there's probably little equity, OP's best option may be to walk away from the marriage with nothing. There's really not enough information here to give a reliable answer.
For example, stbx has a million dollars in debt. What about assets? It is not that terribly unusual for someone in CA to have a million dollars in mortgage debt. Until recently, most of them had more than sufficient assets to cover that - stbx might have $2 M in assets for all we know, so we can't determine whether we're talking about solvency or bankruptcy for stbx.
If OP wants advice, he's going to need to provide more information on assets (both his and hers), incomes, and debt.
