That's what I said, those who have the time, knowledge and resources, which is what you described. I've been to many car forums, I just find more people having issues that have modded their cars versus those that don't.
Example... Aftermarket Supercharged Mustang GT vs Cobra
If you're someone who can afford an 80K car, then you can probably by a mustang and properly mod it. Most mustang owners cannot afford an 80K car, so when they mod their car, it's not uncommon for them to omit supporting mods that are pretty much required for reliable, day to day operation. Like beefing up the tranny when you're pushing 600+ RWHP