After the AFM and injector upgrade, increasing the boost on my Supra was the next logical step for me.  I wasn't ready to fork out the dollars for a new turbo, so I decided to push the one I had a little more.  This meant some type of waste gate mod or control.  There were a few options: shim the waste gate, a manual control, or an electronic control.  I carefully weighed each one, comparing their respective options, strengths and weaknesses and went with the one I could get off Other stuff I needed trader for a good price.  This was the PRofec A.  It seems that many people install their boost controller in the ashtray slot.  My car is a daily driver and, even though I don't smoke, I use the ashtray for trash and stuff and didn't want to lose it.  That meant coming up with a different way to install it.
 

I decided to separate the face from the rest of the electronics and install it in a gutted TEMS controller box.  This meant extending the wiring, with some way to unplug it in the middle, and making a circuit board assembly inside the TEMS box to mount the resistor and piezo to.  I cut the opening in the box just smaller than needed and then made four indents to allow the plastic latches on the PRofec face to click into.  I didn't like the way the PRofec looked in the box at first.  The indent shows along the sides of the face, but not the top or bottom.  I used various grades of sandpaper to smooth this out.  It proved to be easier to tape the sandpaper down and move the box, vice the other way around.  With some trial and error I used a plastic project box and blank circuit board to create the resistor/piezo holder.  I also used two computer monitor extender cables as my wire extension.  They are shielded and proved to have almost exactly the number of wires needed (with a couple extra).  With that done, I can put the rest of the PRofec behind the dash somewhere.  I mounted the stepper motor on unused bolt hole just behind the intake.  This should keep it fairly cool (the manual warns against heat) and allows it to be mounted bottom down (again by the manual).  One thing though, the motor clicks all the time and drives me nuts.  I think I will get some rubber washers and see if I can keep this from transmitting to the body of the car.
 

1- My mod was difficult because of the desire to separate the face which required soldering very small wires to very small pins and manufacturing a board for the resistor and such (what a nightmare).  If it weren't for years of off-and-on soldering experience, I would haven't attempted this.  Kiddies, don't try this at home.  Not for the faint of heart. 
2- If I had opted to install the PRofec together, this would have actually been quite easy with the exception of cutting something in the dash and I probably would have given it a 3 or 4.

1- I can't use this to it's full potential yet since I still have a stock head gasket.  I have the PRofec set on 9 lbs and haven't blown anything, yet.
2- I like the way the install looks, but it's hard to read the display on sunny days. 

Even allowing for the fact that I have a non-metal head gasket and can't push the boost too high, this was a great gain in horsepower.