Traying or "doing trays" refers to a driving technique that is similar to drifting

Drifting (motorsport)

Drifting refers to a driving technique and to a motorsport where the driver intentionally over steers, causing loss of traction in the rear wheels through turns, while maintaining vehicle control and a high exit speed...

. Trays are performed when a fast-food tray is placed under the rear tires and then engaging the handbrake. After this is performed the driver goes forward turning the steering wheel so that the rear slip angle of the car is greater than the front slip angle. causing the car to spin.

History

It is not known who invented traying or when it was invented. But with help from Youtube

YouTube

YouTube is a video-sharing website, created by three former PayPal employees in February 2005, on which users can upload, view and share videos....

 many teenagers and young adults have tried to imitate the stunt and posted their own results online, tempting more people to try it on their own.

Today

Trays may be done because they give the driver an experience of what drifting is and also because traying only wears down the trays versus traditional driftng where the rear tires are worn down and it puts the car in a lot of stress.

The drifting is a derivative of the handbrake turn, as it effectively has the rear wheels locked and the adhesion between the rear wheels and the road surface is broken. Many professional rally drivers can effect a rear wheel drift in a front wheel drive car by applying the parking brake firmly and then releasing it once the balance of the car is upset, more steering input once the rear wheels have broken traction will continue the drifting effect. In European rally driving, this has been a staple method to reduce the inherent understeer of front wheel drive.

Cars

This type of "drifting" can only be produced in FWD

Front-wheel drive

Front-wheel drive is a form of engine/transmission layout used in motor vehicles, where the engine drives the front wheels only. Most modern front-wheel drive vehicles feature a transverse engine, rather than the conventional longitudinal engine arrangement generally found in rear-wheel drive and...

 cars since it is the front wheels are which steer and propel the car forward, versus RWD

Automobile layout

In automotive design, the automobile layout describes where on the vehicle the engine and drive wheels are found. Many different combinations of engine location and driven wheels are found in practice, and the location of each is dependent on the application the vehicle will be used for...

 or AWD

Four-wheel drive

Four-wheel drive, 4WD, or 4×4 is a four-wheeled vehicle with a drivetrain that allows all four wheels to receive torque from the engine simultaneously...

 in which the car is propelled by the back tires or both the back and front tires. Attempting to do trays with such cars could wear down the brake pads on the rear wheels damaging the rotors or drums

Drum brake

A drum brake is a brake in which the friction is caused by a set of shoes or pads that press against a rotating drum-shaped part called a brake drum....

and thus the tray technique can not be performed.

Legal

Performing trays can be seen as illegal because most fast-food trays are stolen from the fast-food restaurant and/or because it can be seen as reckless driving and be punished by law. That is why most trays are done in large and secluded parking lots where the drivers can do the trays without public attention.