I received this email as well a few weeks ago. I just submitted my form and opted for cash settlement as I live overseas. We rented car from Thrifty for 7 days but their records show 6 days. I only have email confirmation of booking and no credit card payment so can not dispute this. Its only $2 extra, and even if I did dispute it and they disagreed they would give me a voucher which would be useless as I live in New Zealand. I have never been part of a class action case so will be interesting to see if we get paid out.