[quote="bitmanEV"]i used this switch from RS; http://uk.rs-online.com/web/p/rocker-sw ... /?sra=pstk
That is just the square version of the switch that comes with the climate control harness. It is a lot smaller than the "slots"/blanks.
It will of course work, but is not any easier to fit than the round one.
It is possible to get switches that do fit the empty slots. However they do not look very OEM/factory delivered, and the terminals are 6,3 mm instead of 4,8mm. And it does not solve the problem with having to remember to turn the switch OFF if you want to preheat.
The new switch harness will include an ON/OFF switch that looks just like the other switches in the car and it fits in the empty slots without drilling. It will have lights just like the OEM switch, and it does not require you to remember to turn it of to preheat.
The latest update:
After some testing with "real live customers" I have to make some minor changes, again. This means that the launch is postponed a few weeks again. The main change is adding terminal "holders" so that is not possible to install the cables reversed. This is not really important to the function of the switch or any potential for damage, but for anything connected to the 12v outlet to actually work. The second change is to change the lights from my favorite color blue, to yellowish/orange to match the other switches in the car.