Aerial length for full wavelength dipole is between 177mm and 235mm for the GPS L1 and L2 signals which would be easy to fit behind the dash. Next job then is to see what the aerial feeder cable and connections are and look for a splitter.

Just seen your latest post Andrew. mmmmmm

I know that TV satellite receivers retransmit down the coax with the signal modulated on a totally different frequency to that received to enable the use of coax. Presumably a powered GPS aerial, again on a thin coax, will be engineered similarly though I can find no reference.

(The satellite frequencies would require a microwave waveguide to propagate properly.)

I guess an "all-in-one" unit can bypass that step so hooking in a remote powered aerial is quite probably impossible.

Thanks for that Ainars. I was/am a bit sceptical as it still relies on picking up the signal INSIDE the car which seems to be the issue with the metallised coating on the heated front screen. But I then noted in the product reviews that someone states that in their car with a "metal oxide coated screen" which previously inhibited signal reception, this device solved the issue. Not cheap at nearly £40 but worth investigating.

EDit: Just seen that although some people mounted the receiver aerial inside on the dash others did mount it as I now think it should be receiver aerial on the outside of the car.

I think, if I read it correctly, that unit could also take a feed from the OEM antenna if you want to access its wiring at a convenient place.

You might be right there Andrew. Heres a link to another site (ebid) selling it at £34.95. The actual seller is Kee Automotive in Chelmsford.

http://www.ebid.net/za/for-sale/ipho...0-74545517.htm

I thought this one looked more interesting, also cheaper and more flexible for use indoors as well.
Depending on power requirements you might be able to totally hide it in a car and use the OEM external aerial. http://www.amazon.co.uk/GPS-Antenna-.../dp/B00LM2GLQM

These devices do suggest that the satellite signal is transmitted (albeit amplified) down the coax without remodulation, unlike a satellite TV broadcast.

Apologies David for not getting back to you, but haven't been in the car since last Saturday. Had a few chores to do today, so took the opportunity of repositioning the dashcam.

http://forum.a8parts.co.uk/attachmen...1&d=1454000986

The red box indicates where it was originally located, and worked fine from. The only issue is the tint making night time footage quite dark.

http://forum.a8parts.co.uk/attachmen...1&d=1454001095

The above image is from GPS viewer software, with a few other windows open as well. What they show are as follows:

1. Folder view of GPS data. Files are created
2. One of the log files opened, which shows zero contents
3. The speed trace which is empty
4. A popup window when you hover over a spot on the timeline
5. Google map of the area

As you can see from numbers 2 to 4, there is no GPS data recorded at all, with the dashcam in the new lower position.

I also let the car run for a minute or so before initially setting off, so that it could get a GPS lock, but no luck. That definitely confirms that the heater matrix in the windscreen does not go up to the tinted area.

If you do opt for one of these additional GPS pucks, it looks like positioning it in the tinted area should give you a GPS lock.

Do you know if Jim even got his dashcam fitted, as it was the same model as mine, although can't remember if he went for the GPS one or not.

This is what I meant: http://www.ebay.co.uk/itm/GPS-Antenn...YAAOSwvUlWqhyC

I guess that might contravene the Wireless Telegraphy Act, but since you're re-transmitting in to a faraday cage who is ever going to notice? The signals can't get in from the satellite, so they're not going to get out again either :)