[RedDevil]

Although a hybrid system delivers more percentual gain in stop and go traffic, it does help on the highway too.
Most of my driving is on the highway in one of the flattest countries in the world, yet even if you try to keep a constant speed the conditions (traffic, on/off ramps, bridges and tunnels, etc) bring lots of opportunities to store energy and reuse that.
Most vehicle types would benefit from having a hybrid system in most conditions.

You can win some for the idea of buying something smaller and more economical, but not all. Anyone would like a better economy, but not if they have to give up what they like.

Don't try to make people drive hybrid cars. Try making the cars people drive hybrid.
Who cares what the best hybrid is, as long as it is better than what it replaces.