Just installed this on my radwagon 4.  Ryan is putting a video together while I am already making a better version of the temporary mount for it.  We were able to fit it hanging upside down from the stock controller position.

My theory is that Rad went all in on trying to customize the riding experience before the pandemic.  Of course the pandemic hits, and all their customizations are getting manufacturing/shipping delays that they didn't count on.  I wish they would have been better at communication up front when they realized all their custom designs were going to be severely impacted, but it is what it is.  I finally got my running board this month, and I was able to score some replacement tubes since I'll be traveling a long distance with the bike and don't want to be caught without one.  I also told Rad when I ordered the bike that I wanted tubes but they weren't available, so they were able to refund me the shipping cost.

Finished product:


Materials:
Seat https://goto.walmart.com/c/2586673/565706/9383?veh=aff&sourceid=imp_000011112222333344&u=https%3A%2F%2Fwww.walmart.com%2Fip%2FBike-Rear-Seat-Kid-Bicycle-Bike-Rear-Handrail-Armrest-Child-Carrier-Bike-Back-Seat%2F165311057%3Fselected%3Dtrue
Knobs and bolts https://amzn.to/3iXPgyK
Roll of neoprene https://amzn.to/372iF8t
Pressure treated wood for seat board and locking block
1 nut to lock knob bolt in place to prevent the bolt from spinning as you tighten the knob
Adhesive to attach neoprene to seat board

This is very much a BETA product, and I can already imagine some improvements.  However, think of it as something to get you started thinking about your own project!

Step 1:
Cut a wood board to fit under the seat.  I used similar dimensions to the deckpad but also made it match a bit more to the seat frame (6 3/4 x 11 3/4).  Cut a similar shape of neoprene for cushion between the board and the bike frame.
Step 2:
Take apart the seat cushion from the seat frame.  The seat should come with some longer screws that you'll use instead.
Step 3:
Drill holes into the board for the two screws that attach through the seat frame to the seat cushion.
Drill a hole in the center of the board for the tracking knob bolt to slide through.
Step 5:
Cut a small rectangular shaped board that will be used with the knob to secure the seat to the frame using the yepp seat mounting rectangle (3 5/8 x 2 1/4).  Feel free to sand the edges as it fits a bit better if it is rounded due to the welds of the frame.
Step 6:
Dry fit everything, make any adjustments as needed, and then paint.  Attach neoprene to board with adhesive.
Step 7:
Attach the seat: https://youtu.be/x5NO0e0bIuc
Step 8:
Ride rad!

Quote from: Altema on August 30, 2020, 08:32:19 PM
Yes, he definitely has that plate on upside down.  Are you going to use a 1/4 inch steel plate on your's? Just curious.

I think I might go a different route with simple pull down straps first.  I'll post pics once I have something working.... still waiting for the bike.

I was able to grab this screenshot from a youtube video showing the underside of the Deckpad accessory.  I plan on doing a bit of DIY to replicate this mount with an aftermarket rack seat once my rad wagon 4 is delivered.  Figured I could post it here in case it helps anyone else.  Note: I believe the guy installing it has the pressure plate upside down  .