It seems like virtually every CC bonus round player followed one of two basic strategies:
1. Reveal each number in sequential order until discovering a match, then (attempt to) resume sequential order until finding another match, repeat.
2. Reveal the squares in two selected columns, usually the first two (1-2, 4-5, etc.) in descending order, until finding a match.
Following along with BUZZR's airings, it seems #1 was the common strategy in the early days, while contestants in the episodes airing recently (from late '88-early '89) tended to prefer #2.
While the latter strategy does have the advantage of keeping the car names more visually organized and thus easier to memorize, it was vulnerable to manipulation--the producers caught on and would place most of the matches in the third column, and almost never consecutively. On the episodes airing today (10/8), the contestant attempted to allay this by choosing the second two columns in his first game (2-3, 5-6, etc.) and the 1st and 3rd columns on the second try, which seems like a good idea, although he was unsuccessful in both.
So which strategy do you think worked best? And finally, were there any contestants who tried something completely different from these--and actually succeeded?