Mine did that recently. Can confirm, it sucks a fat one.
Look on the bright side though mate, at least you don't have a chicken trying to jump through your cat flap to eat all the cat food and crap on the floor!
If you are retaining the stock crossover then you just need to block off the smaller fitting on your new intake pipe.
It is only needed when you remove the crossover.
Seriously though if you spend $22 on a volt gauge and $30 on boost gauge don't expect them to be too accurate.
Also arronm has a very good point. It's hard enough watching my boost and afr gauge that are dash mounted and keep an eye on the road. Looking down and actually getting a reading is a recipe for disaster.
You don't need aftermarket companies for that kind of stuff as it can be custom made easily and cheaply enough if it's not commercially available.
What would prevent or slow mod development in this era of technology is the inability for ecu tuning or trans tuning.
That is a massive increase over stock. My left ear loved it.
I bought mine from eBay Gaz.
It was $70 delivered from a seller called adelaideparts.
Edit: It was a genuine bf sedan towbar wiring loom with reverse sensor and 12 pin plug.
I'm not sure if that's what you mean?
If you scroll to the bottom of the page there are instructions on how to set up the calculator.
In short you pick a turbine wheel size and a/r from the right hand side of the turbine map then adjust the turbine expansion ratio figures until all of the plot points are on that same line.
Edit: The effect on turbine a/r can be found here.
I chose the 1.45 rear housing in my example.
This is the 1.05.
This is the 0.83 and 0.91.
Note in my first example that I had a typo in the afr at 7k rpm. It should be 12:1 not 2:1.
Ninja edit: Play with the values and see what changes.