1) An officer is not required to pull a car over immediately, but may follow it before pulling it over later.2) As long as the infraction you were pulled over was valid--that is, you do have ilegally tinted windows--the stop would be legal; and once legally stopped, you could be required to take a breathalyzer test if there is reason to suspect (e.g. the smell of alcohal) that you may be driving while under the influence.