I found the trick to maintain your car is to have a good mechanic which I do
I was thinking more along the line of advising on the general stuff like wheel alignment, shocks, checking oil, and very general advice. Any more, there is so little that can be done by the owner but one could advise on general stuff. Let's give it some thought
I belong to two web forums that center on Chevy Colorados and GMC Sierras (same as a Colorado, only different maker name)...A general car fix-it web site forum may be too general.
Those forums have been a big help to me with the quirks inherent to that particular pickup truck...especially curing the dreaded, "Passlock failure" where the truck will not start for 15 minuets, then will start normally.
I'm fairly knowledgeable in that area. But I always hesitate to contribute in a non-professional public forum. It always seems to degenerate when someone with far less knowledge and experience chooses to display what he doesn't know, and argue a point to death.