Anyway, why not do that very thing .... changing an acronym like AA into something clever/sarcastic/ridiculous in your actual Welsh.
So ... AA might actually stand for Afiaith am Anlwc.
You can no doubt come up with something better .. so the idea is, as these vans. lorries, shops etc whizz by you as you trundle along, you can try to think up suitable alternative meanings for them ...... what about this one ....
BBC ..... Bawaidd, Byddarol, Cwerylgar !
Once again, have a go at other possibilities for a bit of practice.
One more for the road ..... ha ha .......
Right .... now here's a few for you to try ....