I would make sure I am comparing apples to apples.  There are various levels of BMW as there is of LEXUS.  So, assuming we have the a Beamer and Lexus in same price range, I would probably go for Lexus because you get more car - better quality, higher performance, finer features.  But, due to its longer history, BMW probably holds the higher snob value.

I have not mentioned INFINITY because it probably is not comparable to the above two.  I would say it is at the same stratus as ACURA.  But, again, both of these latter two are excellent cars, just do not have same brand value.

Just my opinion.