DWI Information
You can represent yourself -- although it a terrible idea. It is sort of like a doctor doing an appendectomy on himself.

"Drunk driving" is a very complex field with increasingly harsh consequences. There is a minefield of complicated procedural, evidentiary, constitutional, sentencing and administrative license issues.

A qualified DUI attorney, however, can review the case for defects, have the court suppress evidence, compel discovery of such things as calibration and maintenance records for the breath machine, have blood samples independently analyzed, negotiate for a lesser charge or reduced sentence, obtain expert witnesses for trial, contest the administrative license suspension, etc.

DWI Answers
Breath tests are the least accurate in determining the amount of alcohol you have in your system. This is because the breath machine assumes that the breath is from the lungs when it may be the alcohol residue still lingering from the mouth, esophagus, or the digestive system. If you belch, burp, hiccup, or vomit shortly before testing, or take a "breath freshener" (e.g., Binaca, Listerine), or cough syrups, you can bring vapor from alcoholic beverages still in the stomach up into the mouth and throat, registering an inaccurately high reading that would be used against you. Dental bridges and dental caps can also trap alcohol.

Analysis of a blood sample is potentially the most accurate, since it shows the presence of both alcohol and drugs. The least accurate and least reliable, by far, however, is urinalysis.

Thus, if you are confident that you are sober, a blood sample is the wise choice; urine, being least accurate and most easily impeached, is the best option if you believe your blood-alcohol concentration is above the legal limit.