What are the other environmental impacts of Hybrid cars?

mfox949 asked: I have heard rumors that the manufacture of the nickle batteries is an environmental nightmare in China creating excess waste and the need to then transport these batteries. Then their life span is only about 100K, once that battery is done it is the worst kind of waste, toxic, non-biodegradeable and non recyclable. On your Green Car ratings the Prius gets an 86 while the Mercedes M-Class gets an 8. Did you consider that the Mercedes will run up to or past 300K and is almost 100% recyclable with the exception of the small battery?