Andrew McKay wrote:
As I remarked in an earlier message, I now have a fully working
automatic garage door. However one problem is that if I don't remember
to park the Freelander forward then I'm going to have an expensive
repair job to look forward to, as the canopy door extension bar sticks
out several inches, and will clobber the rear of the Freelander.

The door opener/closer is the Motorlift 5000 from Screwfix.

I need to have some sort of proximity detector which will either
prevent the door from closing, or alternatively beep at me or flash a
light if the car isn't far enough forward in the garage.

Any ideas, possibly with links?
To solve an identical problem I screwed a batten to the floor behind where
the rear wheel would be with the car in the correct position.
Didn't help when I remotely made the door come down on the open hatchback
though :-(