Note - this is about installing a tow bar ON the smart car so it can be towed behind a motorhome; not a smart towing something else.
My husband and I finished installing the Blue Ox tow plate on the smart and it took 2 1/2 days from start to finished wiring. Its not THAT hard, it just takes a lot of fussing around to get things in the right place. I do think the tow plate is 10% too large and that causes plenty of issues with fitting it correctly; but to the details:
The manual on line is great; right up until things get really difficult and then there's hardly any explanation. There are also some errors. They say you need a 3/8 12-point socket but you can use a 10MM one just as easily.
I'd recommend making a tray of sorts and laying paper down so you can label each set of bolts, pins, etc that come off in each step. Plus, making additional notes about where things came from if you had a hard time finding them. It could be days before you reassemble and you won't remember all the details.
The push pins used to connect sections wiggle out with a flat screwdriver that you slip under the edge of flat head.
Step 5 says to use a 25 torx but its actually a push pin that you can wiggle out.
Step 8: the fascia around the antenna and on the passenger side is very tight and comes off from the top, then the bottom.
Step 10: the door panel kick panel needs to be removed carefully with a long screwdriver held horizontally to open the 5 tabs. Some square white plastic keepers will break but still be functional - although I ordered some replacements (and some pins). There are also several spots UNDER the kick panel that have to be pried apart, and retapped together later.
Step 12 leaves out that you have to twist separate a light harness on each side.
Step 14 should say to use a 10MM socket and you can actually remove the bolt by hand.
Step 17 mentions fastening the wheel well out of the way although this isn't needed until step 22. It should say "pull and push, fold and mutilate and generally wrench the thing in half to work behind it." It will require someone to hold it out of the way later.
Step 18 mentions a push pin (besides the bolt) but its just a tab that isn't removed.
Step 19 referenced that 3/8 12-point socket -- use a 10 MM. They should add here to remove the horn temporarily.
Step 20: set the tape circles aside to be reinstalled later.
Step 21: The photo is deceptive; if you download the manual; print page 8 out with a high quality setting so you can see the pictures as well as you can. You have to cut away the bottom part of the cardboard from the drawn white line, down to the fold.
Step 22: Go create a 1/4" spacer from a piece of wood, about the size of a small post-it note.
Step 23: The BIG MISTAKE. Should say SUPPORT BRACKET, not baseplate. This was confirmed with Blue Ox technical assistance.
Now, the dreaded nut plates. Find someone that has dexterity to help you here! We often pre-weakened the nutplate wire so we could break it off easier and on some, we removed it before putting the nut inside. If you can get some "earthquake putty" or "poster putty", stick some on/around your index finger and that will keep the nut on your finger as you blindly try to line it up with the bolt coming to the inside of the teeny box.
Also helpful to do: stuff a rag down into the frame channel (with a string tied on) to catch anything you drop before it rolls to the back of the car and can not be retrieved. (yes, it happened to us)
Step 24: The wire on the whiz bolts was much harder to remove; pre-weaken it a lot.
Step 26: if anyone has any idea how to run a safety cable around this area; let me know. We didn't see a way to do it and didn't. Note; we've towed more than a few cars behind several motorhomes for YEARS. The baseplate attachment to the vehicle is NOT the weak link in the system.
Reattaching the front of the car -- sure, but only after you cut some of the plastic grill out of the way of the tow bar. Gee, a template of where to cut would have been helpful. We attached the front in a temporary way, lined up as well as possible, and started clipping the plastic diagonal grill as necessary. Taking the smallest 'diamond' out and enlarging the cut as necessary. In the end, we had a wide cut out for both the tow bar safety chain attachment and the actual tow bar attachment as one single cut out. It looks fine but was nerve-wracking to do.
Step 28: We dremeled the bevel out of the back of the license plate 'frame' and reinstalled it an inch or so higher; looks fine.
WIRING:
We ran the 4-wire length over the plastic 'drip pan' like plate underneath and to the battery area and came through the existing rubber grommet for the battery cable. Then go under the rug and along the side of the passenger seat to the slope heading up to the engine area. Fishing it through there took some work but once up to the deck, you can get access to each side's tail lights pretty easily.
My husband fabricated a metal bracket to hold the 4-pin wiring plug at the center front of the car, using the 2 tubes on the tow bar provided. The bracket has 90 degree fold to sit against the bottom of the tow bar's cross member and the flat part is screwed into the 2 tubes.
Testing the wiring showed it to be 100% perfect -- but then my husband watches the details...
Phew - it was quite a process but its done and we're ready to tow!
Hey - give me some love here. This was quite a posting!!
Hamp
Did you take pics to document your install? If not, go ahead uninstall and reinstall and get some pics this next time around. 
....but my car is commonly referred to as a frog.
Linear Mode
