I believe the few cars you already see lowered have either prototype springs from say Eibach or another company or they are doing it the old fashioned way - cutting the springs to make them shorter! If you are desparate, find a shop that will cut your springs. Of course the results may be mixed or hit or miss and be prepared to order some extra ones or replacement springs. Good Luck.
Contact/email NYC/NJ area DJ and car tuner
www.funkmasterflex.com , maybe they/he can steer you in the right direction or attend one of the Celebrity Car Shows. Good Luck!