platinum and catalytic converters

Hi,
can someone please clarify something for me.
With 40% of the demand for platinum being in catalytic converters, can someone shed some light on:

1. Are catalytic converters only used on diesel vehicles?
2. Are a greater proportion of vehicles being fitted with them?
3. While growth in motor vehicle sales continues at 6% in China, will this growth offset the reduction in sales from germany/us

I am just trying to work out whether the reduction in motor vehicle production will necessarily translate into a fall in demand of platinum.

Thanks