Yes, the aftermarket industry is huge, but by and large the car manufacturers don’t see that money. And the aftermarket options the auto manufacturers DO provide are rarely anything beyond some visual mods or the odd suspension bits. But that’s not the real reason manufacturers wish tuning would go away…
It’s US! How many times have you heard of people modding their car with nitrous or some form of boost, then blew the engine, and tried to part the car back to stock for warranty work? How many owners of Mitsu Evos (in the states) and STIs crank up the boost, blow shit up, and then expect their factory warranty to cover it? How many NA cars, like Civics, 350Zs, etc. do people **** up in some way or another, with improperly installed suspensions, or hydrolocked engines from running CAIs into a puddle, etc. etc.
The answer, as far as the auto industry (and their laywers) is concerned is TOO much. And honestly, I don’t blame them. I have no respect for people who mod their car which they know voids the warranty for that given aspect of the car, and try and pull something on the car companies. It’s this reason that most cars now are built with tolerances not far beyond the stock power levels… because it’s cheaper than overengineering, and it’s easier to spot the modders.
Now, on the OTHER side, I can’t stand it when manufacturers and their service stations deny car owners warranty work when they discover mods that either haven’t caused any problems, or are obviously completely unrelated to the problem (i.e. having a CAI but you come in with a complaint of a blown stock suspension). Of course, although many dealerships are just greedy, lazy pricks, others take this stance out of necessity, because they’ve been burned too many times by owners that pull the stunts I listed above. Then, you have the car owners who feel they’re justified in these unethical tactics, because they feel (and very well may have been) ****ed over from previous, honest dealings with an unscrupulous dealer.
It’s the “chicken or the egg” theory… which came first? I personally, don’t care, and I don’t think feeding the cycle is the way to go, which is why I take the stance that I do. One thing I am sure of, however, is that we are seeing the effects of these problems with our newer cars. One look at the engine bay of the newest gen Civic Si only goes to support this: it’s more cramped under the hood than EVER before, intended to discourage modders from trying to cram a turbo in there.