[MetroMPG]

Hi rifraf -

1) I'll let basjoos comment on the exhaust routing.

2) The lever for the hand throttle is to provide very fine throttle control when cruising. It's a mod that enables a more efficient driving technique.

When you get fuel consumption instrumentation in your car, one of the very first things you notice is the relatively BIG jumps in fuel consumption from incremental changes to the accelerator position. Changes that are literally imperceptible to the butt-o-meter will show up on an instant fuel consumption display.

The hand control permits much finer adjustment of the throttle once up to cruising speed. It may also be more comfortable to use than feathering the throttle by foot for long periods.