a4 key fob question

[glenandem]

hi guys,im looking for a new key fob on ebay as i only have one and ive got the part no which matches the one on ebay apart from the letter at the end 8Z0 837 231 D, does it matter that the D doesnt match or do they have to be the same right down to the letter?

 

[Mike.M]

The letter represents the frequency of that particular key. I think there a 3 or 4 different MHz frequencies in circulation for audi and Volkswagen

The letter can also be a upgraded part, so would be best off checking in etka

 

[glenandem]

hi pal,cheers for getting back,ive been looking at a few on enay and the ones with different letters still have the same frequency so not sure what that one little letter could be and whether it makes a difference,surely if theyre the same frequency they should fit my car?