@Mikimuster3 is absolutely right, and just to clarify all details, I'll leave an extract from the NFS Wikia page on Abandoned Car events.
"Abandoned Cars are cars in Need for Speed: Payback that were hidden across Fortune Valley and had a rotating window of availability.
They were introduced with the December Update released on December 19, 2017, and the selection of possible vehicles was increased as part of the June Update released on June 19, 2018. The rotation of cars ran from the mode's introduction on December 19, 2017 to the end of the last abandoned car's availability on June 11, 2019." Source: https://nfs.fandom.com/wiki/Need_for_Speed:_Payback/Abandoned_Cars
However, there is one particular vehicle that is COMPLETELY exclusive to Abandoned Car events, the FVPD Ford Crown Victoria Police Interceptor. Luckily, I was able to get one myself. Other players weren't so lucky though, and the car is essentially inaccessible now... I love it dearly and it was genuinely the only reason for me buying Payback, shame the performance level cap wasn't removed and they never added the other FVPD vehicles though. Have a good one!
