I'll tell you how I did it. Firstly you must understand I'm really into music and a friend of mine who is a motoring journalist recommended that I go see Peter. I walked into the shop and mentioned told Peter that him and CV Audio came highly recommended and that I was looking to do audio + alarm for three cars but obviously one at a time.
He took me into his office and sat me down, took out an A4 paper and drew out a diagram explaining in detail how the alarm would work. Until I understood fully, only then did he agree to plan the install. However, for the 350z he was against any ICE due to the complexities involved and the fact that the BOSE system is good enough and to install a system that is significantly better would cost 5 figures minimum.
So we concentrated on the STI and the GTR.
The STI was a Spec C hence only front speakers, no sound deadening, basically nothing. At the time there was quite a number of STIs being stolen some of which were carjacked so I wanted as good an alarm as possible. In addition, the STI already being some 100+kg lighter than a stock STI plus all carbon fibre stuff could afford some ICE gear so I decided on a simple setup - headunit, sound dampening, new speakers up front and 6x9s in the rear plus amp and active sub. That along with the Clifford alarm system (many extras and one-off features will remian forever secret) came up to about 20k.
The GTR was another story altogether. The alarm system was similar to the STI but with more goodies and more than one system (could be 2-3

) independant of each other. As for the ICE, I told Peter my requirements - a boot install with the quality to match and a maximum budget of 30k. The design, layout and choice of components I left to him so it took nearly a month cause they would be re-designing every day and thinking up new ideas which they pursued. I guess its not often that any audo installer is allowed to explore their creativity and experiment with a customers car. I'd get SMS's at 5am cause they would have just finished fabricating something, etc so they did the job as though it were their own car.
In short, I don't think I would ever ever go to any shop other than CV for the simple fact that the first time I walked into his shop, he has gone out of his way to accomodate every one of my requests no matter how trivial. And he answered all my questions and adressed my concerns although at that point he had no idea if I was just shopping around or really serious about doing all of the above. All in all, he spent over an hour just discussing my requirements and making suggestions, etc.
I did what any person would do in that situation. Since the GTR I capped at 30k while the STI was not yet confirmed at the time, I paid for the GTR there and then up front and half of the STI as well. Worth every single penny.