They are using 3 (or more) NASCAR based cars, and they are going for the popular drivers that will help sell the movie to fans of that sport. The same reason that I have the Smokescreen Alternator, I don't care for the character, but I am a fan of the Subaru WRC rally teams.
The only reason that car is marked 48 is because it's the Jimmie Johnson - Hendrick Motorsports #48.

Not everything has to be an Easter Egg for fans.