Amazing.
I have an Amex and as stated before have never been able to use it due to the Zip code issue
I used pay at pump about 15 times in the US a few months ago with my Amex card and it worked every time - no other card that I've tried has. I just used the numbers from my postcode and padded it out with zeros (so AB11 4AA would be entered as 11400) and it saved going inside to pay.