Multifunction antenna

Just wondered if anyone has tried any of those multifunction antennas.
Some of them have all kinds of connections.

We are looking for a 3G/4G (to router) and FM antenna
DAB would be great too as FM will be shut down in a few years.

Sorry if this has been answered before. I did search

 

Ok, so I understand the multifunction antennas are not very good and probably made for people like me who think you can get everything in one package.

But it should be possible to to make a combined FM and celluar antenna, should it not? I am not looking for a shark fin. Just an antenna base that has two external screw sockets. One for the ordinary FM antenna and one aux where I could put a 4G antenna and use the same hole in the roof.

I guess it would look a bit like a V leaning, seen from the side.

Reception is not bad in my country, but from inside a car it can sometimes be hard to get a 3G or 4G signal. From school I remember the car is a Faraday cage.

It would be nice to have this as it is hard to get a cable outside the car in any nice or permanent way.

Does this antenna base excist or will the two signals interfer with each other...?

 

and thank you.
I have seen that too, but I don't think it will work well.
I think it is too much in one place.

Some people get reduced reception just from FM in a shark antenna.