"The Old Man" joke

A self-important young man goes out and buys the best car available: a 1997 Porsche 911 Turbo. It is one of the fastest and most expensive cars in the world. He takes it out for a spin and, while doing so, stops at 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 young man replies, "A 1997 Porsche 911 Turbo. They cost $100,000."
"That's a lot of money," replies the old man. "Why does it cost so much?"
"Because this car can do up to 180 miles an hour!" states the young man proudly.
The moped driver 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, all right!"
Just then the light changes, so the young guy decides to show the old man what his car can do. He floors it, and within 10 seconds the speedometer reads 120 MPH. Suddenly, he notices a dot in his rear view mirror that seems to be getting closer! He slows down to see what it could be and suddenly, whhhoooossshhh! Something whips by him, going much faster!
"What on earth could be going faster than my Porsche 911Turbo?" the young man asks himself.
Then, ahead of him, he sees a dot coming toward him. Whoooooosh! It goes by again, heading the opposite direction! And, it almost looked like the old man on the moped! "Couldn't be," thinks the guy. "How could a moped outrun a Porsche 911 Turbo?" Again, he sees a dot in his rear view mirror! Whooooosh-BLAMMM! It plows into the back of his car. The young man jumps out. It is the old man!!! Of course, the moped and the old man are hurting for certain. He runs up to the old man and says, "You're hurt bad! Is there anything I can do for you?"
The old man groans and replies, "Yes. Unhook my suspenders from your side view mirror."