I'm going to give you all a bit of advice that might just save your asses one of these days.
NEVER, I REPEAT, NEVER CONSENT TO A FIELD SOBRIETY TEST.
First, you have the right under the fourth amendment to refuse. Refusing a field sobriety test is not the same as refusing to submit to a blood, breath, or urine test when under arrest for suspicion of BUI, DUI or any other fancy acronym - YOU CAN NOT BE PENALIZED FOR REFUSING A FIELD SOBRIETY TEST, NOR CAN REFUSAL BE USED AS GROUNDS FOR PROBABLE CAUSE FOR AN ARREST OR AS EVIDENCE OF INTOXICATION.
The burden of proof is not upon you to prove that you're sober, it's upon the L.E.O. to prove you're not, and unless you're completely wasted that's pretty hard for them to do without the evidence they'd obtain through a F.S.T.
Second, they're rigged - okay, technically not "rigged", per se, but they're highly subjective. Things like blood shot eyes, slurred speech, staggered gait, etc cannot be quantified. How does the L.E.O. know that you're eyes aren't always a bit bloodshot, or that you always stagger a bit from an old injury?
Last, No one in the history of mankind has ever been cleared from suspicion as a result of "passing" a F.S.T. Ever wonder why they always follow up a F.S.T. with a hand held brethalyzer regardless of the result of the F.S.T.?
Which brings me to another point - NEVER CONSENT TO A HANDHELD BRETHALYZER - EVER! The results are in-admissable in court. Why? Because the margain of error on the fucking things is between +or- 7-25% depending upon the make and model.
Keep your cans in a koozie - preferably one tall enough that the beverage can't be identified as alcoholic at a glance, crush your empties and keep them out of sight, and never allow a L.E.O. to "inspect" your cooler. Those three tips, plus the advice above makes it virtually impossible for a L.E.O. to develop the level of "reasonable suspicion" required to effect an arrest or issue a citation. That is, of course, unless you're totally wasted, in which case your dumb ass probably deserves whatever comes your way.