
THE AUTO BUILDER
Featured

Standout Builds from the 2026 NSRA Street Rod Nationals Builders’ Showcase
The 57th Annual NSRA Street Rod Nationals rolled into the Kentucky Exposition Center in Louisville, Kentucky, August 6–9, 2026, once again bringing together more than 10,000 street rods, customs, classics, muscle cars, and trucks for four days of horsepower, craftsmanship, and everything that makes this hobby great.

GETTING THE BIG BRAKE
It’s springtime and around here activity is definitely flourishing, as guys prep for all the events they plan to attend. Just about everybody is upgrading their cars for the season, adding a few new parts to really make an impact. This month we bring you an upgrade to Underground Motorsports’ demo 240SX. Stillen big brakes are hot items and we are psyched to present this install.

SHELBY G.T.350SR
The minute you get in, turn the key, and get into gear, you know you’re in a living, fire-breathing machine, and it’s beyond doubt one of the most exciting and easiest-driving cars that I ever handled,” said Carroll Shelby in his 1965 book “The Cobra Story.”
Spotlighter
POPULAR READS
COVER YOUR BOTTOM
A Simple Approach To a Difficult Task
Author
Christopher Sondles
Story & Photography
Simple Bottom-Side Finishing Methods
Other methods of bottom-side finishing are simple approaches, like painting the surfaces rattle-can black or using store-bought, spray can undercoating. Some home builders like painting their undercarriages black while others paint theirs body color. There’s also a selection of undercoating treatments, or you can use any combination of these methods on particular areas. Most high-end, highly detailed cars that are built nowadays have fully sanded and primered under panels that are fully painted in the same color as the exterior, including the clear.
Challenges with Fully Painted Undersides
While this is the best-looking finish, it is the most time-consuming and expensive to do, and it is not the most practical due to damage from road chips and debris. Also, if you’ve ever had to clean one of these fully painted undersides or—even worse—had to touch up the undercarriage after a season of even minimal driving, even though you enjoy looking at these highly detailed cars on the show floor, you know this approach is not for you. If that’s the case, you may enjoy the product we are about to discuss.
The Show Car Buildoff ’55 Underside Coating
The Show Car Buildoff ’55, one of three cars being built by Woody’s Hot Rodz for an eventual shootout, was conceived with several thoughts in mind, not the least of which was the fact that these cars are being built to drive. Taking this into account, Woody’s thought it best to go a different route and coated the undersides of the three cars. Shown here is the ’55, which was the first of the trio to receive this unique bottom coating known as SEM Pro-Tex Tintable Truck Bed Liner.
Chassis Protection and Detailing
While the Art Morrison chassis was double-powdercoated to protect the chassis inside and out and to highlight this high-gloss finish, Woody’s incorporated Totally Stainless fasteners throughout, which are now available in kit form for the AME chassis. To go along with the polished stainless fasteners, stainless brake lines and aluminum brakes from Wilwood provide a great-looking contrast, and the chassis should not only stay rust-free but will also be durable and easy to clean.
Application of SEM Pro-Tex Tintable Truck Bed Liner
To finish the underside project, the SEM Pro-Tex Tintable Truck Bed Liner was purchased from a local parts store (Smyth Parts Plus) in Cincinnati, Ohio. This product is actually designed for truck beds, and because it is tintable (the bed liner is clear to start with), when tinted it will provide a custom look for the underside of this ’55. Another advantage is the fact that the liner material will add another noise barrier in addition to the Dynamat because of its absorptive properties.
Benefits and Installation of the Liner
The installation is simple and straightforward, so follow along as it is applied to the underside of the Show Car Buildoff ’55. This tri-5 will see lots of road miles this summer, but with SEM liner material applied, it will only need to be rinsed off, virtually eliminating any maintenance on the bottom-side finish. For more information on this product or to find a dealer near you, contact SEM Products.
ARTICLE SOURCES
SEM Products
651 Michael Wylie Dr.
Charlotte, NC 28217
866/327-7829
Woody’s Hot Rodz
23950 Salt Fork Rd.
Bright, IN 47025
812/637-1933





