The way to split up the 401(k) is to have a Qualified Domestic Relations Order (QDRO). This instructs your company to disburse a portion of your 401(k) to an "alternate payee." This is pre-tax money that she can put into an IRA. The QDRO is described in the settlement, but executed as a separate court order because it is addressed to the company. The disbursement is done "as soon as administratively possible" and is based on a fixed value or fraction of the total as of a certain date (divorce final), plus or minus earnings on that portion from that date until disbursement.
Don't take out a loan to pay her, because then you have to make the after-tax loan payments in addition to your pre-tax contributions--if you get a little squeezed you end up reducing the contributions and maybe forfeiting the company matching--all bad.
You had a responsibility to pay her car payment? What BS. You CHOSE to do something for your WIFE. If she doesn't want to be your wife anymore, then the perquisites that go with that position are forfeit as well.
