In the Teeth of the Evidence (Lord Peter Wimsey #14) by Dorothy L.Sayers

All that was left of the garage was a heap of charred and smouldering beams. In the driving seat of the burnt-out car were the remains of a body...

An accident, said the police.

An accident, said the widow. She had been warning her husband about the danger of the car for months.

Murder, said the famous detective Lord Peter Wimsey--and proceeded to track down the killer.

This is vintage Sayers, a collection of her finest crime and detection stories.