Note that based on the metal coatings on your windscreens, your reception may be better or worse with a windshield antenna. In my previous Skoda octavia I had excellent reception. In my current Skoda Octavia, having darker windows, reception is horrible. I simply can' t use DAB anymore.
And I simply don' t want to go through the hassle of replacing my FM/GPS roof antenna for a FM/DAB/GPS antenna and completely remove and re-attach the inner roofing material to install the cables.
No, I don't. Of course I searched for it on Amazon, AliExpress and on the briskoda forum, but as I did not want to go through with all the hassle of the inner roofing lining, and in the worst case with a leaking roof, I really can' t remember it.
There were multiple possibilities though and there are videos on YouTube describing how to do it.
@gismo
Just to make sure.
I have one of these "Universal DAB AM FM booster splitters".
I assume that is what you mean?
Note also that I have for my Skoda already a facra-2-fm adapter.
That is why I tried both with a powered and unpowered splitter.
(hardware is really my weak spot 
)
Edit: I assumed that the "Keep antenna always ON" setting will set tthe " phantom power" already on the signal, meaning that I could use the simple splitter.
Or should I use the 12V power on the power cable of the splitter and disable "Keep antenna always ON"?
The last time I tried this was early 2022 in my "new(er)" Skoda octavia. I simply can't remember.
I now remember that I also consulted my garage in early 2022 about it.
If the sharkfin antenna is an active antenna it will have a frequency band filter. Some of these filters do block the DAB frequency.
So I asked whether that could be the case with my Skoda Ocatavia 2015, but nobody knew in that garage.
That could be another reason why I could not get it to work.
Like older antennas from Suzuki before DAB antennas.
They are blocking DAB frequencys to, so no splitter is working.
surfer63 ok all VW (etc) have active antennas though and I have a splitter branded RTA that works for mine. For an active antenna, there are many options, eg at https://www.rta-mobile.com/browse/#/category/528541-1/0/0/0/0/0/0
If you are certain that your antenna amp blocks DAB frequencies then you'll have to swap the antenna or at least the antenna amplifier (have seen replacements somewhere at RTA also, scroll down for Skoda)
surfer63 Not sure I fully understand: My antenna needs 8.5V phantom voltage (same for all VW group) and the splitter uses a 12V input to provide that. I don't remember whether I took the 12V input from the ACC or the motor antenna / amp cable but that shouldn't matter anyway. I left the cable loop on the splitter closed as that configures it for 8.5V, else it would supply 12V phantom.
I got the splitter for about 40 EUR at the time, had it for the previous radios already 
I didn't need a replacement antenna amp, these packages are of course more expensive.
AlieExpress may have similar stuff, at the time I just used RTA because they looked reasonable
I will try again. I really can't remember what I did early 2022.
Something like this for those that want to replace their OEM FM / GPS / 4G antenna, for example - to add DAB capabilities:
Or this with Fakra connectors:
https://www.aliexpress.com/item/1005005715379281.html?spm=a2g0o.detail.0.0.139195S795S7VA&mp=1&pdp_npi=5%40dis%21EUR%21EUR%2041.81%21EUR%2031.99%21%21%21%21%21%40210390c917447968222014810e4f76%2112000034098551679%21ct%21FR%212215045717%21%211%210
Or this withoug 4G (although for those that use 4G SIM card with DUD - the roof antenna should provide better reception:
https://www.aliexpress.com/item/1005008651627827.html?spm=a2g0o.productlist.main.101.b2d15bf9A1r5iR&algo_pvid=440aba3a-c1b1-4d7a-bf03-32734a94d2db&algo_exp_id=440aba3a-c1b1-4d7a-bf03-32734a94d2db-50&pdp_ext_f=%7B%22order%22%3A%223%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21EUR%2139.58%2119.79%21%21%21320.49%21160.25%21%402103846917447966701681881e52dc%2112000046102105273%21sea%21FR%212215045717%21X&curPageLogUid=XACxFsI84mUK&utparam-url=scene%3Asearch%7Cquery_from%3A
