"I own the fastest car" joke

A man goes out and buys the best car available in the US or Europe, a 2001 Turbo BeepBeep. It is the best and most expensive car in the world, and it runs him $500,000. He takes it out for a spin and, while doing so, stops for a red light. An old man on a moped, both looking about 90 years old, pulls up next to him.
The old man looks over the sleek, shiny surface of the car and asks "What kind of car ya got there, sonny?".
The dude replies "A 2001 Turbo BeepBeep. They cost $500,000."
"That's a lotta money!" says the old man, shocked. "Why does it cost so much?"
"Cause this car can do up to 320 miles an hour!" states the cool dude proudly.
The old man asks "Can I take a look inside?"
"Sure" replies the owner.
So the old man pokes his head in the window and looks around. Leaning back on his moped, the old man says "That's a pretty nice car, alright!"
Just then the light changes, so the guy decides to show the old man what his car can do. He floors it, and within 30 seconds the speedometer reads 320. Suddenly, the guy notices a dot in his rear view mirror. It seems to be getting closer!
Whhhoooooooooossssshhhhhh! Something whips by him! Going maybe three times as fast!
The guy wonders "what on earth could be going faster than my Turbo BeepBeeP?" Then, ahead of him, he sees a dot coming toward him.
Whooooooooooosh! Goes by again! And, it almost looked like the old man on the moped! Couldn't be thinks the guy. How could a moped outrun a Turbo BeepBeep? Again, he sees a dot in his rearview mirror!
WhoooooooshhhhhhhhKa-BbbbblaMMMMM! It plows into the back of his car, demolishing the rear end.
The guy jumps out and discovers it is the old man! Of course, the moped and the old man are hurting for certain. The guy runs up to the dying old man and asks "You're hurt bad! Is there anything I can do for you?"
The old man replies "yeah. Unhook my suspenders from the side-view mirror on your car!"