I can tell you about some unusual and strange items that people have been known to strap to the roof of their cars based on previous reports and anecdotes.
One of the strangest items that have been reported is a full-sized boat strapped to the roof of a car. While it's not uncommon to see boats being towed on trailers, seeing a boat precariously perched on top of a car can be quite unusual.
Another bizarre sight has been a fully decorated Christmas tree being carried on the roof of a car during the off-season. People sometimes forget to remove their tree or decide to keep it there as an odd display.
Additionally, there have been instances of people strapping mattresses, sofas, and even an inflatable swimming pool to the roof of their cars, making for some unusual and impractical driving scenarios.
Remember that strapping large or improperly secured items to the roof of a car can be dangerous and may cause accidents or damage to the vehicle. It's always best to follow safety guidelines and secure items properly before transporting them on the roof of a car.