The following morning, Wallis inspected the car and found it to be in a substantially different state than it was when he first saw the vehicle: the bumper was being held on by a rope, the new tires had been replaced by old ones, the radio was missing, as were chrome body trim strips.

The car would not run, because the cylinder head (with bent and burnt valves) was lying loose upon the engine block.

Karsales v Wallis' concept of "fundamental breach" (aka "breach of a fundamental obligation) was essentially a restatement of the "Main Purpose Rule" established in Glynn v Margetson [1893] A.C. 351, the leading case on deviation in carriage of goods by sea.

[5] Despite some reluctance by Lord Denning to absorb the new ruling [6] in Photo Production v Securicor 1980,[7] the House of Lords upheld and approved its earlier decision, thereby signalling the decline of the doctrine of "fundamental breach" The Suisse Atlantique and Photo Production cases together represent the final authoritative statements of the common law on fundamental breach prior to the enactment of the Unfair Contract Terms Act 1977.

The Act provides that some contract terms are VOID (such as limiting liability for causing death or injury through negligence), while others are "Valid only insofar as they are reasonable".