Concerned about the mechanic's diagnosis?

Well, why not get one of these units?  It will record data from your post-1996 model year vehicle and tell you exactly what's going on with it.  Have kids that are driving now?  Plus this in and get the REAL story on how they are treating the precious family ride when you are not in it.  Need evidence to show you were not speeding when you hit that truck?  This will record that information too (or tell you to shut up and take the ticket at the lower speed).  No, it's not cheap, but it is inexpensive when compared to possible service bills if you know there is an issue before it becomes a problem OR you know it is a minor issue before you are billed for a major one.

Besides, it is another cool toy that happens to combine IT and Automotive geekery.

Enjoy.

ThinkGeek :: Car Chip Pro Engine Performance Monitor