Why not just buy a small trailer? For some of you that is one serious option. In another thread is a nifty hitch from Coastal with pics. Now, when I was in Harbor Frieght Tools earlier in the week I specifically went to check on a small trailer that would fit the Prius nicely. And they do have one, a 4x4 foot bed, road ready trailer with small tires that have 4 bolt hole wheels. Comes with lights, everything. What you need is to come up with some bolts, clamps, tie down points or just a sheet of plywood for cargo carried on a flat surface. Or you could built a small luggage carrier on the frame. For those of you who tote canoes or kyacks, this is a nifty solution. the trailer is light, and the price was 200.00 plus tax. I do not think that the weight total of this trailer would exceed 150 pounds or so from the looks of it. To make a luggage carrier, I would build a frame using 2"x 1/2" board and lap nail flashing onto it as a skin with a half inch bottom. Paint the whole works after caulking. This trailer does look like the easy way to go when hauling light man powered watercraft, you can bolt the tie downs where they are really needed. This trailer was outfitted with bearing buddies too, so all you do at the start of any trip is to pump them full of grease until it runs out.
I believe the Costal Tech hitch is NOT intended for towing, and therefore has no place to attach the safety chain, and is therefore unsafe and illegal for a trailer.
Yup, that is it. But the price in the store was 199.99. My guess of actual weight of the trailer was a little off, I thought an actual 150 or so, it is obviously a little heavier with a shipping weight of 185 pounds it likely has 20 pounds or so of shipping material. That is not a bad deal and is a good solution for the light but larger cargo needs.
In skimming through that referenced thread about the Coastal Tech hitch I did not realize that it was not suitable for towing. I am sure that any decent welding shop can cure the lack of attachment points, or recommend a better, more suitable hitch. Question: if you don't tow with it, do you just put a basket or chair lift on it? What is the function?
Coastal Tech designed the hitch without the safety chain on purpose so it would not void warranties. If you drive into a Toyota dealer with a "legal" hitch on, it would be harder to argue that you don't tow with it. With the way Dave designed his hitch, you can easily argue that it's only for bike racks, since it would be illegal to do anything else. I suspect this trailer is just fine for the Prius, and that Dave's (Coastal Tech) hitch is just fine as well. But to make it safe & legal, you need to add a safety chain. But if you do that, then you need to come up with a different story to tell the dealer if you ever need warranty work. (Or get very good at putting it on and off.)
My understanding is that it was designed and intended to hold a bike rack. There are hitches intended for towing. Whether or not this is bad for the Prius, I'll leave to others. Toyota recommends against it.
