Sometimes you may look at trying to get a rental car or vehicle for the purpose of towing something. You may be looking to take a trip and need to haul a boat or camper. It is not something that you will be able to do with a regular car rental company.
None of the major rental providers allow you to haul with their vehicles or carry vehicles with a tow package. Nor, would any allow you to carry one of their vehicles (ie. behind a motor home). It causes a lot of wear-and-tear on any vehicle and would definitely shorten the lifespan of the average rental car!
I would try checking with the various truck rental companies to see if any have pickup trucks with the necessary equipment you would require. Generally, there are packages available on rentals of larger trucks (like a 16 or 24 foot box truck).
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I checked with a prominent boating and yachting site for information on this as it would apply to boats in particular.
It made clear, that a ball hitch on your bumper would never be sufficient if you're looking at hauling a few thousand pounds. If that is the case, one would definitely require a Package set-up that would be connected directly to the frame of the boat that you wish to carry.
There are 4 classes of rated trailer hitches according to gross vehicle weight rating system:
It is very important that the total weight of the boat, trailer, and equipment should never exceed this capacity.
I also checked at Pop-Up-Campers-Trailer and found the same type of warnings. They state that you must make sure that your own vehicle is capable of hauling a camper or trailer. Visit this site for all your questions on pop up campers and trailers.
Because the car rental companies do not allow towing with their vehicles, if you did, you would be violating the terms of your rental agreement.