The importance of the suspension geometry is not lost on most racers, and the principles have been around since the sixties.  (Costin & Phipps was the bible, with the suspension
calculation section done by Keith Duckworth.)

Computers now make analysis a lot easier - 3D modelling would be hard to do on the drawing board.   We offer our
services to analyse your suspension using Autoware programs, Susprog3D and Pederson spread sheets.  We can
also commission manufacture/specify any components required, and do the baseline set up in our workshop.  If it
is not practical for us to see your car, we can send you data
sheets for the info we require.

The important part is to work out how any proposed changes
would benefit the car, or where changes can't be made due
to the rules, how to compensate for any problems.

The latest parity problems for V8 Supercars is a case in
point.  The Ford camp say the current Commodore has more
front grip.  But how can that be?  The Mcpherson strut front
end, as used on Commodore, is generally recognised as having too little camber gain (unless you raise the roll
centre unacceptably high.)  Thus you see a large amount
of static negative camber on the Commodores to try and
get the dynamic camber right.  The Ford wishbone front
suspension should be better. 

I don't know the in's and out's of it.  But John Bowe is quoted in Motorsport News 4-17th of August as saying that the Commodore VT front track is 50 mm wider than the Ford AU!  Now come on Ford camp - what were you thinking of?
To let Holden have a 50mm track advantage sounds way too much to give away unless you get compensating advantages.  

However, they tell us it's all to do with the aero-dynamic package, so I guess we'll see if that's right, after the Fords have had sufficient time with the common front splitter.

It's a black art, that's for sure.  But information is gold. 
Analysing the suspension geometry on your car is a good first step in developing your race car.  It'll give clues to it's
strengths and weaknesses and where improvements might
come from.