West side access to Diamond?

Hi all,

A partner and I are heading to Idaho in about a month - Warbonnet and Heyburn in the Sawtooths and then going for Borah and Diamond at the end of the week. We will be renting a 2WD sedan, and I was wondering how far you all think we'll be able to make it up the access road to the Diamond trailhead? I really want to tick Diamond off my list, but hope it doesn't turn out to be a 20 mile RT without high clearance or 4WD.

Thanks!
Shannon