In Top Drives you can only keep as many cars in your garage as you have Slots available (think of this like space in a real garage). However, you can ‘hold’ any cars you win or buy for up to 24 hours. This gives you a chance to earn extra in-game currency so you can buy more slots in your garage.

To expand your garage with new slots, click on the + symbol in your garage. Alternatively, you can sell cars in your collection to free up space.

If you do nothing, then cars will be removed from the holding pool after 24 hours and that’s them gone for good. However if enabled, you will receive a notification on your phone before this happens just in case you forgot.