If you're doing a holiday in the USA and renting a car via enterprise, Alamo or national book with Rentalcars.com, unless you're flying with doing a Virgin package holiday, in Which case do it with them. They have the best rates in the market due to special agreements. If you want the best customer service experience for rental cars book with Virgin as they will put a lot of pressure on Alamo/national/enterprise who will bend over backwards for you.
I love how you typoed "rentalars" where presumably you meant "rentalcars", but they saw your no-typing ass coming and it redirects to the correct site.