Come race with AMracing http://www.amracing.org fun group. all speeds of cars. They also have time trials etc... the HPDE side http://www.ncracing.org

 

could you not just go through something like NASA where you go through the HPDE levels, do time trials (basically solo I) and then go from there (get your competition license etc etc).

it seems to me like working on the vehicle should come much later on, since a stock '07 STi should be a great for driving in lapping schools etc. also, a stock car is likely to have much better durability than a heavily modified one, IMHO

it costs a few grand a year to track a car regularly in fuel, consumables and maintenance, so IMHO that is another reason to hold off on mods unless you have deep pockets

in any case, good luck!