Safety is definitely one of the reasons why we buy expensive cars. But, not just safety...
check out : http://www.livemint.com/2011/03/24221653/The-curious-economics-of-luxur.html?atype=tp
The linen shirt from Adam Smith is an good example.
NDTV recently carried a report how our neta (of 'aam admis'!) sport a Mont Blanc pen!
Why ?? for the 'social' reasons/peer pressure/et al ! ( blame it elsewhere!)
But it works as a Marketing Placebo... it enhances out performance, born out of our superiority complex!!
PS - all the more reasons for the world to practice 'Ceiling on Desires, to Live SSpiritually!