I live in Virginia, in the Washington, D.C. metropolitan area. My former spouse defaulted on a car loan after we divorced. The car was purchased during our brief marriage. I had credit and he did not; so I became the defacto co-signer. Because of the the divorce, my ex refused to pay the finance company, so the loan accrued interest, penalties and late fees. Last year, the IRS attributed the defaulted loan as additional income to me. I tried to negotiate a compromise, but to no avail. In November 2012, the ITS placed a tax lien. I am working with a tax advocate service to arrange a payment plan. My accountant sugegsted that I sue. Can I sue my ex-husband for his share of this responsibility, which totals nearly $40K? Please advise.