Found on the Fordnatics mailing list, in long thread about movies with
car chase scenes:

>> Well, In case you didnt notice, alot of those neat 'vroom vroom' sounds
>> you hear are dubbed. I also didnt know you could see the tach in the car
>
>You want to hear STUPID!  I was watching a Mexican movie from the mid or
>early '70's.  It involved a lot of car "racing".  Anyway, Fords were
>pretty common in these races, unusual dorky stuff, like a 4 door LTD with
>a hood scoop and blacked out hood.  Looked like a Mexican factory
>option.
>
>Anyway.  To the stupid part.  I suppose since V8's suck down gas and
>Mexicans for the most part are not rich, most own 4 cylinder cars
>probably.  So some schmuck dubbed in a VOLKSWAGEN AIR COOLED soundtrack
>onto the drag races with the Fords!  Talk about weird to watch.