Radio reception?

Have Peugeot Partner MPV, my brother in law lives in France and bought same model over there.
'er in doors' said when her sister in law took her in their Peugeot to town shopping she had bbc radio on clear as a sunny day.

Question what's so special that the car radio could pick up BBC radio so clear yet portable world radios we have in caravan are crap for BBC reception. Once I know why I can then decide fitting a car radio in our caravan. no name on radio so assume made for Peugeot.