Looking at booking a car rental for 10 days for Vegas trip in late August. Have always booked thru Costco and got great rates. The rate however is more expensive with the one booking for 10 days as opposed to 2 back2back bookings (1 week & 3 days). Will I have any problems with linking my bookings if I go with the 2 bookings? The difference is just shy of $100. Currently the booking is with Alamo which is offering the best rate at the moment?