On last week’s trip to the Colorado Software Summit I had the misfortune, for the second time in the last year, to receive a PT Cruiser from Avis. This automobile is a misbegotten failure, despite its admirably idiosyncratic shape and ample headroom. Its ride is unstable and jittery on high-speed turns, its cargo space absurdly limited. Worst of all, it is the single most underpowered car I’ve driven in many years; taking it from five to nine thousand feet of altitude up US Interstate 70 was alternately maddening and terrifying. Clearly they repurposed a sewing-machine factory somewhere to build the engines. Steer clear, I’d say.