Does anyone have a rate code for UNLIMITED MILES on a one-way rental?

I have a valid AWD at a great rate but because the pick-up and drop-off locations are different, I'm getting charged 0.26 cents per mile which adds up to a lot given the distance I'll be covering. I know about the HK code but that's only valid when the pick-up and drop-off locations are consistent. If anyone has a code for one-way unlimited milage, or at least a preferred per-mile rate (that beats the 0.26 cent standard) I would greatly appreciate it!

Thanks in advance... fingers crossed!