Update, I went through 2 lengthy Chat sessions with EA tech support with no results and I was told the game was no longer supported since it was so "old" anyway.
I took one suggestion here and right clicked the Most Wanted game in Origin My Games. I chose "Repair" and it went through about a half hour of checking and downloading after which the message that the repair was successful. I started MW from Origin launch and was greeted with confirmations that I owned the Terminal expansion pack and new cars. Sure enough, the Terminal map was added to my game and I have the 5 new cars available ( the 918 needing to be won of course ). Played the game and all is there for my Terminal Velocity add-on.
Suggest others try the repair process and hope it helps. : ) Happy camping hopefully for those of us playing this game 8 years after release.
