Two instances of a behavior may not count as a rigorously observed pattern, but it appears as though high-profile conductors have a thing for high-powered automobiles.
First there was the great Austrian Herbert von Karajan and his penchant for Ferraris, especially the sound of their V12 engines, which he considered superior to anything he could make a symphonic orchestra deliver. Von Karajan owned a Ferrari 250 GT Lusso, which you could observe first-hand at the Chromjuwelen exhibition in Vienna last year if you were lucky. I was lucky:
(This is the same car which was owned in chestnut brown by Steve McQueen and was featured a few months ago in Jalopnik.)