Scion xB? HHR? Are they big enough for a family vehicle?

[dramaqueen]

We have one son that is two, but is as tall as a 4 year old. We currently have a 4 door Alero that is too small. When either me or my husband are sitting in the passenger's seat there isn't enough room for my sons legs. He is very uncomfortable. My husband is long legged, as well am I. We need something with enough room inside, but still want decent gas mileage. We considered going with an SUV, but with the price of gas (and the SUV itself) were considering something like a Scion xB or Chevy HHR. I'm just concerned about whether they will be roomy enough on the inside. Anyone know?

Also if you have any other comments about these two cars that would be much appreciated. Thanks!