You got your hybrid car. You can add batteries to your car (a known hack) and plug it in to your house current to increase its overall MPG. Why not add solar cells to it as well? It won't help significantly while you're driving, but it'll help charge the car while it's sitting, assuming it's parked somewhere light.
Next, you can use Peltier chips to move heat. There's been some work on using them in air conditioning systems for cars (we're in the early stages) and they're commercially available in some refrigeration applications. Why not make Peltier cooling standard in hybrids? After all, it's gotta be lighter (weightwise) than carrying around the compressor and freon-like chemicals. For that matter, there's nothing stopping you leaving the a/c on when you're parked in the summer, to keep the inside of your car from becoming an oven.
So, why isn't this around yet? I'm no supergenius, and I came up with this using my spare brain power. Thoughts?