Travel Companion & Logistics of dropping off car and flying out

Hi, I am driving a car down to Panama from AZ and looking for someone to come along or caravan with. 30/M, outgoing and I speak spanish

Also, to those more knowledgeable. A friend wants me to buy him a car and deliver it to him in Panama. Is this possible? What is the deal with the duties, how much are they, etc.? Also, if I drive his car down, does the car registration have to match up with my name?...I don't ever remember getting asked for registration when I got stopped in Nicaragua and Costa Rica.

Thanks all