The FM signal is a good point - the D2 uses a complex antenna switching unit which doesn't tend to work with aftermarket radios. An antenna power injector works in non-TV cars, but I haven't tried it in mine yet. If you got the DAB option though, would FM even be needed? I don't listen to the radio.

Not sure if the GPS would work with the external antenna on the D2 - it would need an adapter. Again, needs testing. But, as long as you don't have heat reflective glass its simple enough to stick an aftermarket antenna under the rear shelf.

My main hesitation in buying one is sound quality since they don't publish technical specs for them and you have no way of telling what they have cut costs on. With a Kenwood, Alpine etc Android Auto head unit you know the quality will be there, but you lose the OEM look to get it.

I put an Xtrons Android RNS-E clone into my B6 S4 a few months ago.

Had all the toys and looked great in the dashboard, came with all the cables and was a pleasure to use.

It replaced a Pioneer AVIC 980DAB unit that I wanted to change out as it did not look OEM.

Had more functionality, looked better and offered more.

BUT......

The sound quality was not as good as the Pioneer, noticeably so. I suspect lower spec pre amp stage, just not the same money and R&D spent in that area. Thinner in tone, not quite the dynamic range and this was linked up the the standard BOSE system.

Secondly it had noticeable problem with interference, sometimes there and other times not. All wired/ earthed/ insulated as required I just feel that inside the componentry has less £££ invested in it.

Great if you can get one cheap but the Pioneers and Alpines I have used before have given a better quality of sound.

Would like to keep the option of DAB & FM, some areas in Scotland not great for DAB but FM still works, if the DAB option is chosen (only available on the 2nd one you linked to MJ) where would the DAB signal get picked up from?

As regards sound quality the RNSd non Bose is not great to begin with so would expect even a cheaper option to Pioneer etc to be better TBH. Guess all we need is a "volunteer" to go for one and try it....names on used £10 notes to briang9 C/O A8Parts please+++

That's exactly what I was concerned about. Thanks for the feedback.

Most aftermarket units usually come with a glass-mounted DAB antenna that sticks on the inside somewhere

Depends on your area, many places internal aerial is not sufficient. You cannot use OEM aerial+amplifier as the amplifier only amplifies AM/FM frequency range and filters the rest out so most of DAB will not work. In the A6 I removed amplifier and connected existing cable straight to the aerial. With the amplifier there was no DAB reception at all, without it it's acceptable in the area I live in but it does loose signal in many places around the country but OEM aerial without amp is still better than 2 cheap glass mounted aerials one of which was passive, other amplified. FM radio is also still connected to the OEM aerial and reception is slightly worse than with OEM amp. For best results quality roof mounted amplified aerial something like this https://www.dabonwheels.co.uk/product/jvc-hal-2/ is needed but they are not cheap and I don't really fancy laying cabling and drilling hole in roof so it will do for me as in my area it's good enough.

Interesting discussion re DAB aerials; I think it will be a challenge in a D2.

I've been experimenting with DAB reception in my house, which is in an awful area for TV and catastrophic for DAB. Plus the IR-coated double-glazing reduces signals further. And to add insult to injury, most of our TVs create interference when on that destroys DAB reception.

What I have found is that, on a standalone radio with a whip aerial, the length is critical, and it usually needs to be vertical. Adjusting a typical FM telescopic aerial to about 55/60cm seems to work best, not sure what wavelength ratio that is. A longer horizontal aerial sometimes works, a short one never.

I've also tried a feed from our roof-mount antennae - the only way to get even a minimal Freeview TV signal; so we mostly use FreeSat. That has both TV and FM antennae, fed into a multichannel/mux amplifier to various outlets around the house. Some of these have filtered FM/TV double sockets but many are unfiltered.

IIRC DAB frequencies are between FM and TV (old 405-line band?) and I find that a lead from an unfiltered socket gives decent DAB reception, but neither the TV or FM filtered sockets are much good.
I don't know which aerial (CBA to test as it involves scrambling in the loft!) is actually picking up the DAB signal, but I suspect it's the FM one as it's a multidirectional type, whereas the TV aerial is pointed at Crystal Palace (some way away). The aerial amplifier is probably pretty wideband anyway.

That's all a bit negative, but indicates the challenge you may get with DAB when you leave a good reception area.

Our Volvo has DAB (probably FM too, but I've never investigated) and that actually works fine by our house. Not sure where the aerials are for that, maybe in the rear window and/or roof sharksfin?

And as a footnote, the Freeview TV in my car uses a pair of glass-mount aerials but reception at my house is usually pathetic.
I don't have an OEM tuner anyway, but when I tried to use the TV aerials in my old S8 for DVB-T I was beaten into submission.

Any way of mounting something appropriate within the housing mounted on the boot?
Could it be hollowed out and something more modern incorporated within there?

The housing on the boot is a perfectly good powered GPS aerial, unless it's failed through water ingress, age etc.
It's totally the wrong size for a DAB aerial. :tuttut:

Perfect size for a 4G antenna for in-car wifi though ;)