Announce your car sale in a catalogue of local cars for sale. Ads in catalogues are tolerable because only people desiring to see ads will pick up such a catalogue. Ads placed in places intended to be visible to people who aren't specifically trying to look for ads are the problem. Those ads which try to force themselves on people have an inherently adversarial relationship with people, and therefore we're under no moral obligation to tolerate it. People who make it their business to advertise in that manner are absolute gutter scum.