I have never heard the wag version of 'Vagner' the composer.
I do hear people dropping the ing for in and dropping the d at the end of a word or saying axe instead of ask.

Americans pronounce the er at the end of a word while some English turn it into a soft a. These are more like language pet peeves than witticisms.

The thing about English is that it is the official language of the sky and is spoken by all professional pilots when flying. You just can't say Mayday unless you are in a life-and-death situation.