[rules-users] syntax question

Hi, I have a question regarding rules syntax particularly with left hand side. Suppose I have the following condition .. when Customer ( $cars : cars, age > 18 ) ... How can I use the bind variable "$cars" in subsequent statements without using eval(), like so ... when Customer ( $cars : cars, age > 18 ) eval( $cars.contains( "Honda" ) ) .... Basically I would like to know what the alternatives for doing something like so this without having to use eval function. I know this might not be the best example for this question, but please I'm just learning this system right now. Thanks in advance, Bruce.