Hmm.... Here's a collection of traffic cars for the player, but unfortunately they replace cars with traffic.
Here's the replacement:
FORD RAPTOP F-150 SV --> Dodge Ram 1500 Laramie
FORD FOCUS RS500 --> Infiniti G35
MASERATI GRANTURISMO STRADALE --> Dodge Caliber R/T
RANGE ROVER EVOQUE --> Nissan Frontier
TESLA ROADSTER SPORT --> Chevrolet Cobalt LT
AUDI RS3 --> Audi A3

Installation:
Select the car you like and copy it to the Need for Speed(TM) Most Wanted\VEHICLES folder so you don't have to worry. I made a backup folder.

MAKE BACKUPS
MAKE BACKUPS
MAKE BACKUPS