Originally Posted by poodlelover
Thanks for all the good advice, it is really appreciated. One more question, and I'm sure this is a dumb one, but how do we tow a car? How does the car attach to the Sprinter? Where would I buy this attachment?
Despite ggoat's exclamation of dismay— I think he already knows this response will be long and wordy— you've come to the right place. I tow my car behind my Interstate. I can't necessarily tell you everything
you need to know, but I can tell you what I know, which is at least some
of what you need to know.
First, you need to find out if your car is towable four-down (on its own wheels). The best source is your car's owner's manual. Check it to see if towing four-down (also known as "dinghy towing") is listed in the manual, and see what it says. Do not confuse dinghy towing with emergency towing. They're not the same thing at all; a car that's capable of being dinghy-towed may not
be capable of being emergency-towed four-down. There are reasons for that, but I won't go into them; this post will be long enough as it is.
If your owner's manual doesn't say anything about dinghy towing, the next source for this info is Motorhome Magazine's annual "Guide to Dinghy Towing." Each annual issue only lists that model year's towable cars, so you have to find the issue for your car's model year. You should be able to find it online; Google "20xx Guide to Dinghy Towing" where xx is your model year. For example, my 2013 Honda Fit is towable four-down; 2014 Honda Fits are not, due to a change in the transmission. Only models that can be dinghy-towed are listed; if yours isn't listed, that generally means it can't be dinghy-towed.
If the car is not towable four-down and it's front-wheel drive, you can get a towing dolly, a two-wheeled trailer that carries the front wheels of the car. No modification to the car is needed. The weight of the car plus the weight of the dolly must be within your Interstate's towing capacity of GCWR minus actual loaded weight of the Interstate. Tongue weight of a dolly is almost always within the receiver's tongue weight capacity.
If the car is not towable four-down and it's also not a front-wheel-drive, then you'll need a car carrier trailer, that puts all four wheels of the car up on the trailer. As above, the trailer plus the car together must be within the towing capacity of your Interstate, and this time you'll have to also be concerned about tongue weight; getting the car balanced just right on the trailer to make sure the tongue weight is correct may take practice.
In all cases, it's worthwhile to load up your Interstate to full travel loading— people plus gear plus full fuel, propane, and fresh water tanks— and go to public scales to find out your actual loaded weight, which is then subtracted from 15,250 pounds to find your true towing capacity. Extended Interstates also have a reciever capacity of 500 pounds tongue weight and 5000 pounds towing weight, so if your actual weight is less than 10,250 pounds, then 5000 pounds is the maximum for car plus dolly or trailer.
Assuming that your car IS towable four-down, you'll need three things for the car. The first is towbar baseplates. These are permanently mounted, and custom-fitted to the make, model, and year of the car. Installing them typically involves removing the front bumper and front body panel, unless you're looking to tow a Jeep Wrangler where it's a simple bolt-on installation.
The second is towing lights, meeting the requirements for trailer lights in your state (except backup lights, you can't back a toad/dinghy). Three ways to do this. First is to tap into the car's own lighting, with blocking diodes having two inputs (original car electrical and umbilical from tow vehicle) and one output to the lights. Second is to drill the taillight housings and insert separate bulbs for the towing lights. Third is to use magnetic mounted temporary lights, which I personally don't like. If you've got to permanently add baseplates anyway, might as well permanently add towing lights as well.
The third requirement is supplemental brakes. I went with a permanently-installed supplemental brake system that incorporates a vacuum pump tied directly into my car's power brakes. Removable systems that mount in the driver's footwell are more common, but have to be removed before you can drive the car, but have to apply a lot of force because they don't tie into the power brake system and have to make up for it with brute force on the pedal. My permanently-installed supplemental brake system also includes a breakaway switch, so if the car is disconnected from the motorhome somehow while the vehicle is in motion, it will brake to a stop automatically. I don't know if the removable supplemental brake models have that feature.
Fourth, you need a towbar— yes, I said above you need three
things, but this is for the Interstate, not the car. I use a receiver-mounted towbar that remains hooked up to the receiver; that type tends to be easier to hitch up and unhitch than the bumper-mounted A-frame towbars.
Of course, you'll also need an umbilical cable, to connect the seven-pin connector on your Interstate to a six-pin (usually) on the car. Although depending on the way you hook up the towing lights, you might only need a four-pin connector on the car. If you use magnetic-mount lights and a removable supplemental brake system, than all of your wiring might be temporary as well; otherwise the connector on the front of the car is usually mounted under the front bumper.
Depending on the supplemental brake system you use, you may also need a brake controller mounted inside the Interstate. My supplemental brake system doesn't need a brake controller; it's activated by the brake light wiring, so if the brake lights come on, so does the supplemental brake.
There are several compnies that make the necessary components for towing. The only ones that are custom-fit are the baseplates. Blue Ox and Roadmaster are the main players in that field, with the widest selection to fit your car. One caveat; the two compnaies use different connecting devices, so if you get Blue Ox baseplates you'll need a Blue Ox towbar as well, and if you get Roadmaster baseplates you'll need a Roadmaster towbar.
That's a lot of information to digest all at once, but now you know as much as I do about towing a car behind your Interstate.