Compared to the Prius' prosaic looks, the Insight is quite dramatic.  The front may be Honda Civic, but behind the A-pillars, the car sweeps backward in a teardrop shape that is pure aerodynamic efficiency.  The aluminum wheels look like solid discs, and even the rear wheels are hidden within the body.  

The rear looks like the 80s Honda CRX hatchback, with Mitsubishi Lancer lights grafted on.  Between the lights is a rectangular window, allowing the driver to also see through the vertical portion of the hatch when backing up.  

Since the Insight is smaller and lighter than the Prius-the Insight weighs about the same as a City-it contains a much smaller engine.   The gasoline unit is a 1.0 liter 12V inline-3 with VTEC-E, the Economy VTEC which keeps one intake valve nearly closed until higher revs demand both intakes to open wide.  It's one of the lightest of its kind at about 56 kg., making extensive use of lightweight aluminum and magnesium. The engine is good only for 67 bhp and 91 Nm but inserted between the engine and transmission is a very thin electric motor-so thin it acts as the engine's flywheel.   The motor, part of Honda's Integrated Motor Assist (IMA) system, is good for 13 bhp and 50 Nm of torque.

At low speeds, the electric motor spins along just like a regular flywheel; the 1.0 acts alone.  When needed, the electric motor draws power from the Ni-MH batteries and boosts the drivetrain output to 73 bhp and 125 Nm at a very low 2000 rpm.  

Results? The Insight whines its way to 100 km/h in a quick 10.8 seconds when fully charged.  That goes down to about 13.5 seconds when the batteries are depleted.  That's still faster than the Prius, which takes about 14.3 seconds when fully-charged. 
 
When coasting or braking, the IMA goes to generator mode and tops up the batteries, just like the Prius' motor.  Part of the IMA is the Engine Stop feature:  When you come to a full stop, simply shift to neutral and release the clutch, and the engine stops completely.  When it's time to go, depress the clutch, shift into first and the electric motor instantly spins the engine back to life.

Despite its front, the Insight is not a modified Civic.  It's an all-new design with a highly rigid all-aluminum unit-body.  The skin is bolted and welded onto a cast and extruded aluminum frame, composed of cross-ribbed hexagonal aluminum extrusions.  The chassis itself is an innovative piece of automotive manufacturing.  The car does feel light, such as when you swing open a door, but it's very solid on the road.

The steering wheel and dash are similar to the Civic, while the body-colored seats add some visual excitement.  The Insight's display is divided into three sections: engine status on the left, speed and fuel economy in the center, and electric motor status on the right.  It's clear and entertaining as you try to squeeze more km from each drop of gas.

Each carmaker's interpretation of a hybrid vehicle is reflective of its maker.  The Prius plays to Toyota's forte of building reliable, practical family sedans, while the Insight's two-seater hatchback speaks of Honda's sporty side.  Toyota also designed a more practical steel structure for its car, while Honda created an aluminum structure and new assembly techniques for its car.