@usmanulamin: Yes, you are right that how can we see the car at so much speed, but its acceleration is so mush fast that it can easily reach to 120 within seconds, personally i haven't tried yet but watch this, than you can get how we can measure speed of it and really it goes 
134mph speed run R/C car - YouTube
@BackToCivicFaiez: 2.4GHz 3 Channel Radio System, Distance range: More than 100 feet ~ 150/160 feet