There are some reports that National Car Rental, or more likely, someone who works (worked) for National Car Rental may quite possibly have been involved in credit card fraud schemes in recent months. If you do a search of these forums, you will see some recent discussions about credit card frauds reportedly involving National.
Several posters, including myself have experienced fraudulent use of credit cards after dealing with National in the DR. To be sure, National, or anyone who works for National have not yet been publicly implicated for credit card fraud as of yet, that I know or heard of??..................