Carrie gets a greasy no-prize for bringing us this WaPo article about the radical changes in auto maintenance:
Components that were once purely mechanical -- brakes, steering, suspension -- are now either electronic or controlled by computers. It's still possible to spend a Sunday afternoon tinkering on your Lexus in the driveway, if by tinkering you mean changing the oil. Otherwise, most home mechanics are restricted to cosmetic changes, such as installing a new sound system or putting light-up dragon heads on the wiper fluid nozzles. Almost anything that makes a car perform better is going to involve electronics.
Which is why I tinker with the Spider, but I take the Cruiser to a mechanic.
However, there's still a whole host of things that really are purely mechanical, even on new cars: bushings, bearings, tie rod ends, ball joints, struts, radiators... the list goes on and on. Of course, as the article notes, if you want to make a car perform better, you'll definitely end up at a computer screen at some point.
Even then real performance gains are still mostly mechanical. In spite of the "tuner" mindset, re-chipping or re-programming will typically only get you an extra 5%, tops. To go any further requires new pistons, re-worked heads, different gear ratios, turbos, etc., all of which require a lot more wrenching than programming.
And that's just when you're trying to make, say, a defenseless Honda Civic HX go faster. Going up the food chain into vehicles designed for high performance (Corvettes, Cobra Mustangs, Trans-Ams and Z-28s, those Mitsaru R4TYSi8-Evo things, basically any Alfa) means the factory is already doing all the easy stuff for you. Making those go significantly faster automatically means you're taking apart the motor or major chunks of the suspension.
With these cars though, there's no free lunch... modifying them for major performance gains will always result in degrading their streetability. Some folks (typically men between 16 and 25 with no family) think that's fine, and hey why not... it's your vehicle and your money. Others think a kidney-punching roller coaster ride isn't much fun when all it really does it get you to the grocery store 2 seconds faster.
In case you haven't noticed, I tend to fall into the latter category. As far as I'm concerned, I'd rather spend my money on a car that's already got the fast bits designed in at the factory. After all, they're in the best position to do it and do it right. Yeah, assuming my "Pennies for Alfas" program actually yields me a new 159 in a few years, I may succumb to the temptation of a computer tweak or two. But then again, maybe not.