Wouldn't the propper translation be "THE old English cars are not fast" or "Régi angol autók nem gyorsak."
if you want a literal translation, maybe.
Difference is that for the same use case, english doesn't put 'the' in front of words while hungarian always does
"Regi" and "oreg" both translate to old. If you mean "regi" as in antique, you should say antique.
I'm also confused over why "Régi angol autók nem gyorsak" was not accepted?
You need 'A' at the beginning, like "A régi angol autók...." . See my comment above.