There are a number of possible reasons why a Mini Cooper won't shift out of park. Some are specific to the Mini Cooper's design and internal components; some are general faults and failures that can happen to any car with a gearbox or shift lever. Working through a list of potential causes may be the most cost-effective, simple way to identify and treat your Mini Cooper, but remember not to compromise your safety purely to reduce costs.
Remove the gearshift collar. The shift lock may not be disengaging when you try to shift out of park, so try unscrewing the collar and console from around the gearshift and take a look at the lock inside, which should engage and disengage with each shift. Release the mechanism manually by inserting a pen underneath the lock and lifting upwards, and add grease to each component to free them up and create an easier, smoother shift in the future.
Remove the shift stem, which could be the source of the issue, particularly in the region of the thumb button which you depress when you change gear. If this button has lost its connection to the shift stem and other internal components, the shift will not engage properly. You can remove the shifter handle and pull the shift stalk upwards to release it, but this may only constitute a temporary solution. It is likely that doing this once will not completely resolve the underlying issue. You will also require a button resetting tool to re-engage the thumb button.
Unjam the shift cover. Occasionally, small objects like coins can get inside the components of the shift box. Try searching for anything that may be causing a jam and, if you find a foreign body, pull it free. If you fingers won't fit, try tweezers.
Fix the cardanic axle. A dysfunctional cardanic axle will cause stripping of loose wires under your car, which not only results in the failure of connected components but is also dangerous. Short circuits can blow the fuse responsible for the engage/disengage function of the shift mechanism, which you operate using the thumb button. Cut out faulty wire with wire cutters and replace with new electric wire.
Repair a faulty brake pedal shift switch or ignition switch. Not all cars have these, but if your does, it may be the cause of the problem. Check and repair if necessary by having new switches installed or the old ones reconnected and serviced. If you are also experiencing problems with your brake lights, this could be related and will give you a clue as to why the gears won't change properly. In this case, you need your brake light switch repaired or replaced. Your local dealer or mechanic should be able to source the components and complete the repair for a reasonable cost.
Check your battery. This can lead to shift problems in the gearbox. Recharge or top up your battery using a mains operated charger device if necessary. It's useful for any motorist to have one of these chargers in their boot or their house in case of low battery voltages in colder, damper months when discharge is more common. According to M Power, modern battery chargers are safer because they have a specialist "terminating" function.
Check the transmission fluid. By upgrading to a synthetic fluid and maintaining the levels, you can avoid most costly transmission component repairs. Some mechanics will also "readapt" the transmission to improve performance of the gear lever mechanism.
Most mechanics want to fix your car at a reasonable cost, but it doesn't hurt to run your own quick check on how much a component is worth new before deciding whether to repair or replace it. If someone does try to charge an amount that doesn't sound sensible for the work, check it before agreeing to the work being started. This avoids unnecessary conflict and cost.
Do not attempt potentially dangerous wiring repairs or battery charging if you feel uncertain about what to do. Read about the subject carefully, and consider getting free advice from a local mechanic even if you want to save money and time by completing the work yourself at home. In America, the gear components are called "Transmission," but in Britain they are referred to as the "gearbox," as explained by Car Bibles.