automotive anorexia

A psychological disorder in which the subject is obsessed with the belief that his vehicle has excessive weight. The patient will engage in destructive behavior such as stripping out seats, mats, and even mechanical parts in order to attain an unrealistic standard of automotive performance, agility, and fuel economy. If left untreated it can be life-threatening, especially when parts needed for safety are removed from the vehicle.
This condition can afflict anyone, but it is most common among ricers and boy racers.

"Mark took the passenger seats out of his Honda Civic".
"That's nothing, he also took off the spare tire, the muffler, and replaced the windows with clear plastic."
"He's got automotive anorexia, we need to stage an intervention before he tries to take off the air bags and somebody gets hurt".