Well it just comes down to the dollar sign at the end of the day.
If they choose to market more efficient cars more effectively, they'll have a growing market. If they choose to rest on their laurels and let the consumers buy what they've already been told they want, then that's what will continue to happen.
To manufacture more fuel efficient vehicles the initial costs would be exhorbitant and that's the only thing stopping the big guys atm. When they're either forced to do it, or realize that fuel for cars as they are now is starting to get a bit more thin on the ground, they'll have to bite the bullet. After that, they'll just tell consumers they don't want big huge gas guzzlers. What they want is something sporty and economical.
