HT Games
Costumes
Adults participating in car rallies get to relive their teenage years by riding around in cars and having fun doing silly things. Have all participants dress up like their teenage self. They can wear the clothing of the era when they grew up -- '60s, '70s, '80s or '90s. If they can fit into them, they can even wear some of the outfits they loved as teens. Other costume theme ideas might be having everyone cross dress -- men in dresses and heels, women in some form of masculine attire whether suits and ties or trucker caps and T-shirts with rude messages. The men might have to apply lipstick inside a local sports bar; the women could chew tobacco and spit on the sidewalk outside a beauty salon. Each event would be photographically recorded or even uploaded to a car rally website.
Physical Challenges
At one stop along the route, have the oldest team member in each vehicle walk on their hands -- someone can hold their legs up if necessary. At the next stop, everyone must stand on one leg in the parking lot without holding on to anyone or anything for as long as possible. You could have all team members ride skateboards through a church parking lot -- be sure to have protective gear for head and joints. Take pictures to record everything for posterity.
Items That Go Together
Have teams collect items at each stop with the final step being putting the items together to make something. For example, people might pick up a mixing bowl, eggs and other ingredients, a spoon and a baking pan then have to mix everything together to make a cake. Have teams collect the necessary tools and equipment to build a go-kart. Or, have everyone collect seemingly random items including some glue and have them put everything together in some kind of sculpture.