I have seen them on Amazon - here are a couple...

http://www.amazon.com/Wald-Rear-Bask...9313482&sr=8-5

http://www.amazon.com/Wald-Folding-B...9317162&sr=8-9

Is that what you are looking for? If you have nylon grocery bag type panniers, the heel issue will be the same with these too.