I currently have a mechanical speedo gauge using a cable from the now removed Type 9. As far as I can find on the internet the Mk3 MX5 took a speed reading from pure faith and had no need for a speed sensor. So I'm going to need to go for a stand alone electronic speed sensor attached to the prop shaft. Is there a way of making an electronic sensor power a mechanical gauge? I'm reluctant to go through the cost and hassle of buying a new gauge and have the odometer adjusted.

Is there a problem with bolting the electronic sensor to a live axle differential, given that it will be moving around, albeit not in relation to the prop? Where can I buy the sensor?

The opperating system for the mechanical speedo is of a totaly different style to the electronic type, so no you cant get a mech. unit to work using an electronic sender, although you "may" be able to swop the internals into your clock, but probably not worth the hassle. HTH Ray