Fitted the box at Asda on the way home. Popped the bonnet, took my box in, did a bit of shopping and then opened the bonnet on the way out. The wait ensured any residual charge in the common rail sensor socket was gone as per instructions (they say wait 5 mins after opening the bonnet and then locking the car back up).
Fitting was a cinch. Pop the plastic cover off the engine (it just pops off its 4 frictionally held pegs), find the common rail sensor socket at the left end of the common rail, pull the socket out (remembering to push the locking tab down as you do it otherwise it won't come off). Plug the corresponding 2 sockets (1 each of male and female) of the tuning box wiring strap onto the exposed male and female ends of the plug you just unplugged on the common rail assembly.
Similar thing with the air inlet box on the right side of the engine block (the socket is on the left of the air inlet box) - unplugging the plug from the socket (again pushing the locking tab down on the plug as you pull it out) and plugging the other end of the box wiring strap into the socket and plugging the now loose plug with the other part of the wiring strap. It takes literally 90 seconds. Then plug the box into the wiring strap and tighten up the finger screws. You're done. Start the engine up and make sure it's purring without any warning lights being thrown up. You then have to decide where you're going to use your cable ties to secure your wiring strap to existing hoses and then secure your box so it doesn't rattle. Another 90 seconds. Put the plastic engine cover back on - line up the oil filler cap, and press the 4 pegs down - all secure. You're done.
Can't take pics now. Didn't have the camera with me when I did it, and it started raining as soon as I got home. It looks pitch black now. Pics tomorrow - weather permitting. I left the box on it's default middle setting 4 of 7, supposedly the best blend of power and economy - primarily because I didn't have a small screwdriver on me to open the box and change the jumper settings.
On the drive home, I had 2 stops that I wouldn't normally make and the car indicated 43mpg (what it has been doing on the last few commutes except this morning when it cracked 47mpg). I didn't put my foot down much, but the car seemed to have more power with less throttle pressing.
Not exactly sure whether the indicated mpg will increase with this box. Will the car work out it's mpg based on what the pre-altered sensory signals sent from the ECU would say the quantity of fuel the car wants to use (1), or whether something meters actual usage irrespective of the sensory signals sent by the ECU which subsequently get altered by the box on the way to destination (2).
Scenario 1 would have the car thinking it is using more fuel than it may actually be using (if driven economically), so you could end up with the car saying it's almost empty when it actually has a gallon more than it thinks it has (based on 10% gains). Conversely, you could be hammering the car and it ends up with less in the tank than it thinks it has.
Scenario 2 would have "accurate" mpg readings (within accepted variances) and you would see the gains or losses associated with the box straight away.