Soft
A car that's lacking is really soft. Cars need to be hard so that things like bugs and other cars wont hurt the people inside when you hit them. But if your car is lacking the hardness it needs, you'll have a really soft, useless car.
Picture a soft car lacking what it needs to drive down the road. It's so soft it just flops down and won't move.
なん
やわ
None
This car is probably so soft because it's made entirely of naan (なん). Naan may be delicious, but it makes a really crappy car. No wonder it was so soft (and yummy).
Picture trying to drive this soft naan car. It probably just sinks into the ground and then gets eaten by wild animals (and me).