[COcyclist]

The VW engine tray serves several purposes; especially in the diesel it is a sound deadener, it keeps grit and spray out of the engine compartment, and it helps with aerodynamics. The VW is fairly flat bottomed from the engine back, and even has plastic filler panels in front of the spare tire well to smooth airflow in that region. In cold regions the tray helps hold in engine heat- the diesel warms up slowly but gets the best mileage when fully warm. Some VW owners install a metal skid plate in place of the plastic one to protect the engine from chunks of ice and snow on the highway.