u should definetly get ur brakes cheked out. ABS stands for ANTI-LOCK BRAKE SYSTEM. it works with all weather wet or dry, it prevents the wheels from locking and screeching to a stop in case u have to brake hard in an emergency. the ABS allows you to steer the car at the same time while braking hard. if u dont have ABS then if u brake hard and ur wheels lock up, u cant steer ur car atleast out of danger to avoid an accident. it keeps the wheels rolling while still slowing u down at a steady rate so u can stop without hiting anything and or steer out of the way of shit because the wheels are still rolling(but slowing u down at the same time) and not locked up and screeching to a stop. i think something is wrong with ur brakes. maybe they dont come down enough on ur rotors to slow the car enough. if it was the abs then also u wouldnt have the vibrating going on. that might be ur pads rubbing against ur rotors and something going wrong there. ??????? u should get ur brakes cheked as soon as possible.