The 10 year OEM thing is a myth. If an automaker discontinues a car tomorrow, they are not legally obligated to continue supporting it at all if they don't want to (other than fulfilling outstanding manufacturer warranties for those cars...and they will need parts to do that.) If it is a popular model, there might already be a lot of OEM parts in the channel, as well as substantial aftermarket parts support. That could keeps parts readily available for years.