EXT input?

[CB91710]

The U1000 has an unused input marked "EXT" that is not documented (that I could find) in the manual.
Is this for an external GPS source, or an item on the roadmap for a yet to be released accessory such as interior camera, or video monitor out?

 

[BlackboxMyCar]

That is used for internal firmware updates by Thinkware.

 

[CB91710]

Thanks.
I had a feeling it wasn't for the end user.