supersprints are good fun and good entry level.
to give you a run down...
A skyline is to go into class SVD.
Its against the clock - but you are in a class.
you dont race for position on track as its not a race,well, more a race against clock and quickest lap wins.
in SVD class, you'll be up against GTR's, EVO's, highly modified commodores and falcons etc - most will be street registered. in fact I think they have to be street registered to be in SVD
My MX5 is 2B which is 1600-200cc and street rego'd with some modifications
There is the CAMS state supersprint series, and there is also the interclub one. I have done a a couple rounds of the CAMS one but 2009 I did the interclub one with southern sporting car club. 2011 I'll hopefulyl do 4 out of the 6 rounds.