Boosting radio aerial signal

[Pennee]

I’ve got a 2008 Itineo (fiat Ducato base) and I’ve changed the base unit but the signal is so poor. It cuts out more than it’s on, when tuned into general radio stations eg radio 2, radio 1 etc.
Does anyone know how to boost this signal please. I don’t seem to have an outside aerial so presume it’s in a mirror?
Any miracle purchases you can recommend?

 

[Mikeco]

I fitted a roof mounted ariel which seems to work better than the original one.

 

[Landy Andy]

I’ve given up, and just stream radio via my phone. That always works, even when abroad.

 

[Pennee]

I’ve given up, and just stream radio via my phone. That always works, even when abroad.

This is what I’ve been doing lately as it drives me nuts! I kept loosing the 4g signal on that on my last trip (admittedly Welsh hills) so thought I need to ask the question just in case