Hi all,

I should be picking up my TCH in the next few days and wanted to get a general concensus on undercoating a TCH. I notice that the rear wheel wells have a shag like material on them and was not sure what or why it was. I'm guessing that this is some sort of sound insulatation so I suppose it should not be undercoated over. Also, what does undercoating do to the drag coefficient of the under carriage?

Thanks

I would never get undercoating. Cars are made much better these days and don't have the rust issues like they did when undercoating came to fame.
Save your money

The material in the rear wheel well is sound insulation material. It's to reduce the sound of water splashing against the wheel well (among other uses) from entering the cabin.

Mods: EV mod, VVT-i emblem, sport pedals, OEM cargo mat, JDM Prius interior footwell lighting, Sylvania Silverstars 9003ST, DICE iPod kit, OEM all-weather mats, TomTom ONE v2, LED licence plate lights.

The shop would really have to know what they are doing. Sometimes putting an undercoating on top of what already comes with the car (which is already excellent) can comprimise the factory application. Why? Well an undercoating put on at the dealer (or wherever) can plug holes that should NOT be plugged. You don't ever want to trap water (or salt). A careless application can do just that. In fact you have to be very careful not to plug anything.

undercoating are only worth it if your car didn't have one to begin with, which is never the case with new cars. so no... they are not worth it.