The annual Motor Trend International Auto Show opens tomorrow at noon at the Baltimore Convention Center. More than 500 cars, not all makes and models, but lots of makes and models, from the ultra-expensive to the very practical. Some run on gas, some on electricity, some on a little of both.Last year, we visited the auto show with a young man who knows an awful lot about cars: Rory Cahill. His expertise and opinions on all things automotive have attracted the attention of a lot of folks.On two occasions, General Motors has shipped a car to Rory’s house and asked him to try it out for a week, and give them his unvarnished opinion. In the biz, he’s known as “an influencer.”So this year, we have invited Rory back to talk about the latest cars – which ones he likes, which ones he doesn’t like, and why.We aren’t going to be able to visit the auto show together this year, but Rory has kept up with the latest industry developments, and he joins me in the studio. Full disclosure: Rory is the son of one of our producers, Kathleen Cahill.There’s only one thing Rory doesn’t know about cars: how to drive them. Rory is 14 years old -- two years shy of getting his license.