The book I’m seeking was written in the 1960s or 70s. A young lady (probably a teenager) was going on a cross-country road trip with her grandmother. They were to meet up with her boyfriend coming from the other direction. The girl drove, not the grandmother. They each put colorful pieces of material on their antennae so they could spot each other on the road. At some point, the ladies decided to give a ride to hitchhikers who ended up ‘hijacking’ them and holding them hostage as they drove for days. Eventually, all turned out well and they met up with the boyfriend.
It sounds like something Phyllis Anderson Wood would have written.
Kelly,
I looked up her plots summaries, http://phyllisandersonwood.com/plot_summaries.php and unfortunately, none of them fit my scenario. Thank you for the suggestion!
Take Me to My Friend by Hope Dahle Jordan. 1962. One of my favorites. I still have it!