lowering Q45 question

hi guys and gals, i recently bought 99 Q45t and it because its touring, it has these buttons for suspension, Auto or Sport. i was thinking to lower the car couple inches but donno because of that touring thing. and i donno if it will mess something up if i lower it. but if i can lower it without any problems, what kind of springs should i buy, or whats the best way to lower it. and where can i get them. thanx to u all