I was struggling for a while about where to put my seat heater switch. I wanted somewhere accessible, but out of sight as I'm going for the old-school look. I thought about under the dash, in the ashtray (on the tunnel), and just leaving them loose under the seat so that they could be pulled out. Then, as I was looking at the instructions again (for the I-don't-know-how-many-time) and I saw the reference to a 20mm hole for the switches. Well, I'm using a piece of tubing under the front mounting point of each seat to get just a little more lay-back than the Breeze seat pans provide and wouldn't you know - they were just about 20mm I.D.: