HUD for car?

Hello everyone.

I am looking for a HUD for my car that connects via the OBD-II port on my car. So far I have done the following before I buy:

1. Locate the OBD-II port in the car
2. Use phone to test if the display can show the image clearly on the display (EG Sygic HUD). Some windshields have double glazing and you see double unless you use a HUD sticker.

I have looked at all of them, and I fancy this one:

http://www.ebay.com.au/itm/311014594595

This is a newer model ASH-4 I think it's just all white and looks nicer. I actually want one that shows which gear I'm currently in.

There are so many brands on eBay that I'm not sure where to look.

Does anyone have any experience using these? Are their non-Chinese brand out there that do this? I know that GARMIN has one but it's apparently useless without the companion product and doesn't have as many features as the Chinese ones.