When I was car shopping with my mom a few years ago(2012) we looked at the Fusion, Regal, LaCrosse, Sonata, Kia Optima, Mazda 6, and the new for 2012 Camry. So I'd say they do get cross shopped.

Personally out of all of those cars I liked the Regal the best for its great handling/ride and very tight build quality. I don't think mom could get past the perception of the Buick being an old lady's car, something her mother would've driven. The Fusion was the old 2012 model, and we both agreed that it(the old model) looked very dumpy/dated. She ended up with the new 2012 Camry, although if she had been shopping a year later I think she might have ended up with a new Fusion or Accord, those were both great designs that came out for 2013.

 

Sure--lots of cars get cross shopped that are in different segments ... like a Regal and a Lacrosse from your personal experience. Someone nay naturally think "If I'm going to spend THAT much on a Kia, should I consider an nicer car?" Or vice versa--"Should I get a base Buick or a loaded Kia?" That doesn't make the cars in the same segment.