Don't totally give up Missy! Just be prepared for the worst in case it happens! As long as you have a carrier with you and can get him in it quickly then it won't hurt to try a short outing to see how it goes first. I didn't mean to be discouraging just trying to prepare you in case it goes bad. It really is impossible to control a freaked out cat without lots of stitches!
You never know for sure until you try! Boomer could surprise us all and LOVE it! A short car ride is a good way to start and see what happens.
Keep us posted! We know you love Boomer and we do to!!

btw-I love that picture! He's just hanging out!