Ok, since it is listed as being co-owned, as personal property, if husband passes with out a will, the FL intestacy laws would control what happens to any personal property. The law states that his spouse would take half of his estate
and any children by him would take the other half.
732.102 Spouse's share of intestate
The intestate share of the surviving spouse is:
(1) If there is no surviving descendant of the decedent, the entire intestate estate.
(2) If the decedent is survived by one or more descendants, all of whom are also descendants of the surviving spouse, and the surviving
spouse has no other descendant, the entire intestate estate. (3) If there are one or more surviving descendants of the decedent who are not lineal descendants of the surviving spouse, one-half of the intestate estate.
So yes, stepson would inherit his father's half interest in the vehicles unless they are titled "XXXXX XXXXX OR Sue Jones" if there is no will in place that disposes of his assets entirely to you or the vehicles are transferred to you solely prior to his death.