What is the ruling on selling cars via microphone in showrooms without the buyer being aware of their defects?

Selling under the microphone (i.e., by auction) with a condition of absolution from defect is a matter of disagreement among jurists.

The Hanafis permit it, and the seller is absolved from every defect, whether known to him or unknown.

As for the Malikis, Shafi'is, and Hanbalis, they hold that this sale is not binding, and the buyer has the right to return the commodity if an old defect is present. This is the more preponderant opinion.