Since my 6 day rental will meet the 4 Day 3 hour minimum rental required. This means I should be able to return the car after 6 days, and be charged at the same daily rate x 6 days (instead of daily rate x 10 days) right?
Yes, that is correct.
If you want, track it with AutoSlash and we'll let you know if we find a better deal. You can also PM us after submitting it for tracking and we can set up a parallel request for your desired dates as well. You never know--the rental companies may, at some point, relax the minimum date restrictions and we may be able offer you a deal for your actual rental dates.
Have a great trip!