Following the 2007 Formula One espionage controversy the MP4-23 was subject to FIA inspection before the start of the 2008 season, to determine if any Ferrari intellectual property was on the car.

[3][4] After an admission that the Ferrari information was disseminated more widely throughout the team than was originally thought an apology by McLaren on 13 December 2007, and a pledge that measures would be taken to rectify the situation, caused the FIA to decide that there was no need for a formal hearing and the matter was considered closed.

[5][6] As part of updated FIA regulations for the 2008 season, the MP4-23 as well as the other cars of 2008, used raised headrests in an effort to improve driver safety.

Revisions from the MP4-22 included a longer wheelbase, the removal of the "bullhorn" winglets from the airbox and a new rear wing which differed both in main profile and its endplates.

The livery did not differ much from that of the MP4-22: grey remained the primary colour, while red, together with the main sponsor Vodafone, appeared on both wings, on the sidepods, above the body and on the side vents.