Im 100% behind this but the only way I see this happening is by
1. decontent the car " make A/C option pw pl " Renault has been doing this for quite sometime so I think that Nissan will go this way
2. using aluminum frames "LR will do it because they are a luxury SUV maker but I dont see Nissan been able to make and Altima it would make the car too expensive
3.making the cars smaller like in the past
Well it's a good thing your not an engineer, because there are plenty more ways to reduce weight:
1. Use a turbo 4 cylinder engine instead of a V-6.
2. Use non-steel material for hoods, trunk lids and roofs.
3. Don't use a full-sized spare tire.
4. Make alloy rims standard. Use magnesium instead of aluminum.
5. Use thinner gauge steel on non-safety critical parts.
6. Improve design. For example, use a single piece interior door molding instead of screwing together several pieces. In the seats, use memory foam instead of metal coil springs. Or use a single HID headlamp unit instead of multiple halogen bulbs.
7. Use fiber optics instead of copper wires.
8. Improve the CAD of the frame to eliminate material where it does not add to the strength of the frame.
9. Offer manual transmissions in all models.
10 Switch to a single, larger diameter exhaust rather than dual exhaust pipes.