Alright, the acid test results:
Got a Hollywood rack from Biketek--Express I think--with an adapter bar. The rack was easy enough to set up, but I had some difficulty with the adapter bar because my handlebars are adjusted very high and for some reason, I can never get the bolts to loosen with my hex keys. Also, the way things went, the adapter bar didn't quite fit in the rack as easily as I had expected, but that was more easily solved.
After wrestling with the bike a bit, I decided to stop by Trek before I got on the road and the mechanic nicely came out and brought my handlebars down for me. Thank God.
I'm pretty pleased with the security of the rack, although the bottom straps will slip off my trunk every now and then because of the way the bottom of my trunk is. However, I used extra bungee cords and, after a little resetting at a rest stop, the bike didn't budge going up the steep hills in W.Va. and western Ohio.
Thanks to all for the advice, esp. for the "sock on the pedal" tip. It really helped a lot to have all this info!! Happy bicycling....