Is it really possible to drive onto a trailer like Knight Rider?

There is no reason why not. As Galileo noted, the important thing is your relative speed not the absolute one. So if the trailer is doing 60mph and the car 70mph, once the car is on the trailer it will only be doing 10mph relative to the trailer. So it would be like driving onto the trailer at 10mph. The one problem you could get is that if you don't make the transition with your foot on the clutch, the wheels will go from 70mph to 10mph while the engine is still trying to push them at 70. This will either cause a lot of burnt rubber or bits of your engine to fall out.