navig. extra weight?

The weight from the NAV system should be minimal... Although everything helps. There is a reason why they have "small" people ride as jockeys on horses.

This car is a long way from being a lightweight... I wouldn't worry about the weight of the NAV system.

Perfect???

If they got this thing under 3000lbs the performance would be noticeably improved. Heavy cars may feel more stable when cruising on the freeway, but they have more trouble with quick transitions (like on a slalom course).

Also if they got the weight down it would improve the fuel mileage.

Weight is also hard on tires & wheels.

If they did build the car with less sound insulation, and relocated the car battery to the rear trunk they could have made it weight less and still have similar front/rear weight balance.

There are lots of other ways to reduce weight as well. I am sure they _could_ have found ways to use lighter weight components in the engine compartment if light weight was a high priority.