Train,
I've got a yellow box, although I'm not familiar with the speedo healer. The box seems to be a good choice for me. It let's you offset by +/- 27% . That's alot of error correction. I put some 220 guages on my '03, and it looks like I've got it dialed in pretty close. If you're not doing something like that, then it should work great for you. You can adjust in .25% increments, so you should be able to get it dead on. The box itself is tiny (about 1.5" x 3"). You splice it in to the speed sensor wires, and place the box remotely. I've got it in the trunk. A suggestion: get some shrink wrap and do up the wires coming from the box, as there are three separate wires. The box also has a quick disconnect plug, so you can take it out if you're worried about getting it wet when you wash up your baby. Because it has exposed micro-switches, they recommend that you keep it dry. You can put it into a small case (like the ones that electronics wizards use for their projects), and it should be dry forever. Installation is easy and the instructions are good. (None of that "translated from Chinese to Apache, then English stuff"). The product is made in Australia. OK, that's enough. Good luck!