My alternatives to point 1.
* Remove: spare wheel (replace with compressor and can of goop), boot lining, everything from the glovebox and centre box, coins, loose mats.
* Replace seats with light weight ones and battery with small, light hi-tech unit.
* Operate with 1/4 tank fuel max, 1/4 tank washer fluid
* Pump tyres up
There's a 30kg benefit in the fuel alone.
2. You can buy hand held GPS/UHF radios that have this feature.