Mini has announced the production of its three millionth car since 2001, and its two millionth international export.
The three millionth MINI to be produced is a 5-door Hatch Cooper S and has a special exterior design to celebrate its heritage and its British roots.
A £750 million investment is underway across three of BMW Group's UK manufacturing facilities.
Highlights include a new 1,000-robot bodyshop at Plant Oxford and the installation of new body manufacturing technologies including laser welding at Plant Swindon.
Unite has hailed BMW Group's decision to invest £250m into its UK plants in Oxford, and Swindon as a "ray of sunshine".
The company announced the cash boost during a visit by Business Secretary Vince Cable this morning.
Tony Burke, Unite assistant general secretary, said: "This major boost in investment is tribute and reward for the dedicated and hard-working workforce at Oxford, Swindon and Hams Hall.
"The British car industry is once again a ray of sunshine in gloomy times for British manufacturing.
"The UK has the potential to be a manufacturing success story, if we had a Government which was prepared to roll its sleeves up and intervene to support employers up and down the UK."
BMW is to invest £250m in its UK Mini factories, including those in Swindon and Oxford, over the next three years.
The announcement was made during a visit by Business Secretary Vince Cable to the Oxford plant, on the day when the Olympic Torch Relay will also pass.
The announcement comes on top of a £500m investment promise in June last year.
BMW said the investment showed its commitment to Britain "as a vital manufacturing base".
BMW has announced a new pay offer following discussions with the UNITE union, in the hope that a strike at its Mini plant in Oxford can be avoided. In a joint statement the company said: