Whose son went missing in the Sahara Desert during 1982?

Sir Mark Thatcher, 2nd Baronet (born 15 August 1953) is a British businessman. He is the son of Margaret Thatcher, former Prime Minister of the United Kingdom, and Sir Denis Thatcher, and is the twin brother of Carol Thatcher. Mark and his twin sister, Carol, were born six weeks prematurely by caesarean section on 15 August 1953, the same year that their mother qualified as a barrister. Their early years were spent in Chelsea, London.

On 9 January 1982 Thatcher, his French co-driver, Anne-Charlotte Verney, and their mechanic went missing for six days in the Sahara Desert whilst driving a Peugeot 504 in the Paris-Dakar Rally. They were declared missing on 12 January. His father flew to Dakar, where a large-scale search was launched, including six military aircraft from three countries and Algerian ground troops. On 14 January, the Algerian military spotted Thatcher's party 50 km (31 miles) off course. This caused international embarrassment to his mother. The Prime Minister insisted on paying £2,000 personally towards the cost of the search, and an unpaid 11,500 dinar hotel bill, one third of which was for drinks, caused diplomatic embarrassment.