I've wired most of the sensors for the DigiDash unit, but needed to do the speedo. I've glued two magnets to the bolt heads (the sensor needs to be 1mm away from the magnets, and the bolts seem a logical place for them).
I then used a length of aluminium plate to hold the sensor itself.
Next, I fitted the DigiDash to the dashboard itself, and span the wheel to read a speed (I got it to 13MPH).
The round pads on the steering wheel are to hold the pad in place.
I then spent a lot of time putting cable ties around all the wiring to keep it everything in place.
Note that I've put an addtional switch to the left of the steering wheel for the horn.
I've used over 100 small cable ties, and about 50 large ones. The only wiring I need to do now is wire the senders for the DigiDash (6 of them) and the ECU itself. However, tomorrow I'm going down to Portsmouth to get the exhaust TIG welded.