The OP probably subtracted wrong.
It looks like he made the trip in the 2015 truck with their Palomino on it ... which probably was more recent than 2 years ago.
P.S. to the OP: I really like the Anza Borrego area too and would like to explore it more in our small Class C. I'll bet is was really a great place to explore in your grandfater's day - with less crowds and maybe less restrictions on where you could travel and camp there.