There are faster ways to chop up the Beetle, but the steps outlined below get consistent results and greatly minimize the risk of a misplaced cut, damage to the wiring harness, or injury. Always wear suitable eye, hand, and ear protection.
1. Rear cut lines
Mark a line between the two impact mount upper bolts that just touches the bottom of both body plug holes and passes through the bottom third of the center harness grommet hole.
At the end on both sides, extend the line along the top of the impact mount until it reaches the vertical edge. Then turn 90-degrees up passing about 1 inch from the wiring grommet. Drill a small pilot hole at the impact mount intersection (this helps relieve metal stress of a sharp corner cut and will be smoothed out later).
Using the alignment line, extend the cut line beyond the wiring grommet and pass about 1/4″ from the two holes in the sheet metal (the left side only has one hole). Then make a 90-degree turn (exact position doesn’t matter) and exit at the hatch lid frame.
Make the cuts (a combination of cutoff wheel, reciprocating saw, and drill are recommended). The back end scrap can be removed as a single piece. When completed, the chassis should appear like this:
Grind down the cut edges to remove burrs for safety; more complete treatment will come later.
2. Rear tray test fit
Remove both upper impact mount bolts and replace with longer bolts supplied in the Smyth Ute kit.
When tightened, a stud end will extent inwards. The rear tray part in the Ute kit has two tear drops at both ends with a location pierce.
Drill out this pierce to at least 5/16″. Then fit the rear tray so that these holes pass through the impact mount bolt studs. Fasten with washers and a nyloc nut.
3. Chassis alignment check
With the rear tray securely fastened, take an edge-on rear photo to check alignment. The two impact bolts are critical attachment points. If the tray doesn’t sit level and square with the chassis, the assembled truck bed won’t fit properly. Now is the time to address any problems with the Beetle chassis.
4. Edge weatherstripping
After the alignment check, remove the rear tray. Applying edge trim (not included in Smyth kit) along the horizontal cut. This will prevent rattles since the round rubber seal snugs up against the rear tray, and will help protect the area under the truck bed better than the “raw” edge.
5. Rear vents
Pop out both rear vents. The original thin rubber flap can be replaced with a thicker material to help keep out dust and debris.
Air will still flow under the truck bed, but this is not less important since the vents no longer interact with cabin air.