idea

Pre-Requisites
1 Android Device
1 iOS Device
No Root or Jailbreak Needed

This was discovered while sending cars from a backup account to a legit account.

Key
A = Android device
B = iOS device
Steps

1.) Send a race from B to A.
2.) Have A raise to Pink Slip Race.
3.) Have B accept the race.
4.) As soon as the lights come up, Foul and Lock device A as quickly as possible. (not quite same time, but literally as close as possible.)
5.) Finish the race with device B, leaving device A turned off until the race is over completely.
6.) Device A and B should both now have the cars, just repeat