My favorite road trip was with my late dog 7, driving from Grand Haven, MI back home to Austin in my VW Thing:
Top down the whole way, 7 in my passenger seat, stopping for gas and tacos along the way (me: 2 bean, him: 2 beef, extra hot sauce). Just incredibly fun for the both us us. It took us about 22 hours straight through, and by the time we arrived back in Austin I had the most incredible tan I've ever had in my life....that is, until I took a shower. Open-air road patina FTL.