I have cars that run reasonably quiet without the body - then the noise is amplified when the body is attached. This seems more true with Fly, Scalextric, Carrera than with Slot-it and ScaleAuto - the latter two run nearly as quietly with or without body. The Fly/Scaley/Carrera cars have mating surfaces between the body and the chassis, while the Slot-it and ScaleAuto bodies basically envelope the chassis with less body/chassis contact. So is it safe to say that close contact of the body and chassis is a source of amplification of the sound?
Seems likely, as related to a guitar box being tightly bonded. If so, is there already a practiced method to lesson the amplification that results from this?
Thanks