Hi. I have managed to get a June 17 to June 26th minivan rental through Dollar for $421. Using the klm code, I would be able to get a minivan through National for about $390. National also allows a secondary driver for free rather than charging a $11 per day fee like Dollar. Although, my husband will likely do all the driving it is nice to have the option. I also noticed they include some insurance coverage. As a result, I was tempted to switch my reservation to National. However, I have recently heard that there are not a lot of minivans at National. A couple people told me they booked minivans but when they got down there, there were none on the lot. With a family of five and associated luggage, I cannot risk not getting a minivan. I would rather just pay the extra money and stay with Dollar than risk it. Anyone encounter such problems with National before???