Last time I bought a new car, this was actually a pretty important factor for me -- one car was nominally cheaper, but had a number of optional safety features (like rear passenger pillar airbags, IIRC), and they brought the price to parity with the other car I was considering. I figured I'd hate myself if I declined to buy some optional safety features and ended up with an injured passenger as a result, so ended up including all of them in the purchase price, and eventually went with the higher-base-price car.