If you want to see what TM's are all about try to register a Porsche name. I am a proud recipient of the Legal TM letter from Porsche. (nothing came of it but I got rid of the names real quick).
Apart from the TM issues, Ford and Toyota will never merge. Toyota are the richest ccar company in the world and will soon overtake GM in being the car company which prosuces the most cars world wide.