We use a belt setup that comes out of the nose and attaches at the sides of the long round tubes. Unfortunately, I can confirm that the setup works great. We use out of date seat belts in a 'Y' and then use a strap to come forward. It is strong and still lets you open the hood.
The back is pretty straight-forward as well:
Just a standard tow hook attached with d-bolts.
The through-the-hood setup doesn't strike me as the way to go for a couple of reasons. First, I think they look ugly. Granted that isn't a safety consideration, but if you have a choice, why have them look bad and disrupt the visual appeal of the cars.
My biggest reservation is over how the thing works in it's intended role. At many of the tracks we just have a truck who pulls out of the mud/gravel. They typically are pulling from their tow hitches which is pretty low. In the case of a gravel setup, that means the car actually gets pulled down and into the gravel, defeating the purpose. A hook on the bottom pulls the car up and out of the gravel.
The through-the-hood tow hook does have advantages in situations where the entire car has to be lifted up, but this isn't the most common situation. In fact, most cars with conventional front tow hooks end up losing the hook if the accident is so bad that they want to lift the car up straight with a wrecker crane. Most tracks just take the 'good' end and tow the car or put it on a flat bed. It is extremely rare that they lift the entire car into the air.
We're playing with an idea to adapt the coupe setup to the spec racers and the preliminary look suggests that it will work. It is cheap, easy, unobtrusive, and if it works, it will work better.
If you need more pics on how ours attaches to the coupe, let me know.