There are no concerns over cannibalization of sales. When you compare sales of high end SUVs/CUVs to their brand siblings that are sedans, the bigguns win, hands down. Cayenne outsells Panamera. X5 outsells 7-Series. Q7 outsells A8. RX outsells LS. This is typically at least 2:1, and often as much as 3:1 or 4:1. In terms of worldwide sales, expect Model S to reach around 50,000+ per year and Model X to climb to perhaps 150,000 per year. The highest percentage of Model X will be sold in North America.