evidence suppression -please help

I live i florida and i was pulled over at a routine traffic stop, like where they pull over every third car, well it was at night and they were pulling people over and you had to make a right and turn down this residential road. i didn't see it so i made a legal u-turn and pulled over respectfully. while they were checking my license, they had dogs on the scene and asked to search my vehicle. i didn;t know if i could say no, so i said yes. they didn't find anything in the car, but then they had the dog sniff me and i had 2grms. of marijuana on me. I never gave them consent to search me. can they search a vehicle without probable cause? i had done nothing wrong! The evidence was not in plain sight and i did not give them consent to search my person. Can the evidence be suppressed??
My lawyer just wan't me to take a class and get 6 months of drug testing to have it dismissed or pay and get it withdrawn, but i don't see how the search was legal! Even if you could help me find information regarding the legalities of those traffic stops or info on search & seizure - It would help me sooo much!!!!