The sexiest cars, boats and motorcycles and other stuff have curves, like a woman. Hard chiseled women are not attractive and neither are machines with chiseled lines. Those are only attractive if your a Cylon. Lamborghini countach excepted.
+1
IMO, sexiest cars of all time (in no particular order):
'62 250 GTO
'67 275 GTB/4
Eagle Speedster