I finished all the undercarriage preparation yesterday and spent the day today painting the underside of the Mustang.
I used Dupli-Color TR250 Bed Coating on all of the undercarriage. The coating is very durable but is not as thick as most bed coatings. There is texture but it is very faint. I put a total of three coats on the underside of the car which was five 16 oz cans.
I touched up some areas on the firewall and then painted the toe boards. The firewall is painted with the Krylon 1613 Semi-Flat Black paint. I then used some tape before undercoating the toe boards where they angle back from the firewall. You can faintly see where the toe boards were welded into place but you would really have to be looking for it to notice.