Tell her:
1) it's actually an EFFICIENT vehicle--if you short shift it with a big engine, you may roll into the 16+ mpg
2) it's HEALTHY---there will be no residual animal lard on your heart-valves after a couple "winds-prints"
3) it's SANITARY---it eliminates all post-nasal drip and routes it directly to the occipital region--where it's misfiled
4) it's PRACTICAL----you can actually leave for work several hours late and get there early!
5) it's the most FUN you can have in public with yer clothes on
THEN (when all else fails---) buy her a Bimmer convertible (my wife's will be used, of course---I'm a retarred teechah!)
G'Luck!!!!