My 360R had the washer bottle located under the plenum in the engine bay, which make filling it almost impossible, because coolant hoses ran on top of it. My 420R kit now has the washer bottle relocated to the boot, which is good and bad in equal measures.

I like the fact it’s easier to fill, but it seems to be totally left to the builder’s own discretion how to fit it, and this topic is not covered by the new manual (v1.2 and v2.0) at all. It also goes without saying that this also takes up some of the limited boot space you have.

I have seen two positions used for the washer bottle by Caterham, either on the fuel filler cover or next to it mounted on the side skin. While at the factory, I did raise the question and the reply was that they prefer to fit it on the side skin. Caterham use one of the rear wing bolts and drill a second hole in the side skin to add a second fixing.

I prefer the “next to it” option, but don’t want to drill a second mounting hole in the side skin. In addition, I wanted to replace my rear wing bolts with the nylon alternative (post IVA), so felt a single mounting bolt wasn’t going to be an option either. So I decided it was time to act like a “real” kit car builder and make a bracket.

My idea is to mount the washer bottle bracket to a bracket I was going to fabricate, using two rear wing mounting bolts. I will make the bracket thick enough so a pop riveter can be used to attach the washer bottle bracket to my bracket without touching the side skin. I started by making a cardboard template. The important part was getting the holes in the correct position.

I ordered a small length of aluminium bar 200mm x 30mm x 6mm from eBay, then marked and drilled the holes I needed. I also had to enlarge the bottom middle hole on the washer bottle bracket, to allow for the M5 wing fixings.

I didn’t attempt to copy the shape of the cardboard template, it wasn’t necessary, also I didn’t fit the pop rivet for the trial fitting, because I will send it to my local powder coater, so instead I used a tie wrap. This should give the support I want without drilling additional holes, and when the boot carpet is fitted and the bracket has the satin-black the finish I want.

Tools Used

  • Drill
  • Hack saw
  • File
  • Centre punch
  • Hammer