Car key

From Tardis Wiki, the free Doctor Who reference
Car key

Car keys provided access to cars.

Donna Noble left the keys of her car in a bin on Brook Street for her mother to find while asking a woman to point her to the bin. (TV: Partners in Crime)

The Twelfth Doctor claimed that a Tivolian would give their car keys and bank details to a goose. (TV: Under the Lake)

When the Eleventh Doctor and Rory Williams were trapped aboard a cyber-ship, the former used a car key to summon the TARDIS so they could escape. (COMIC: The Doctor and the Nurse)