You have now gotten to the point of imminent arrest (spoiler alert!) Now what?
NEVER agree to perform physical sobriety tests. These are the tests where the officer wants you to touch your nose, balance on one foot, etc. The officer may request you take it roadside or at the station. Nobody ? and I mean NOBODY ever "passes" this test. Everyone who takes this test fails it, and gives the officer mountains of evidence to use against you. He will sit in front of the jury and talk about all of the dozens of "indicators" that you were intoxicated based upon your performance. It will all sound terribly scientific (and terrible) to a jury, when it is really nothing more than biased observations from a biased test. There will very likely also be a video of you performing difficult physical challenges with which you are not familiar, while under a tremendous amount of stress, wearing imperfect shoes, while you are probably very tired (since most DWI/DUI stops take place late at night, or in the early morning hours). This combination is a recipe for looking "drunk" to a jury, and that's why police try and bully you into performing the tests. If you are asked to perform a physical sobriety test, you should simply say, "I'm very tired and I am not familiar with the tests. I'll take them if I can have my lawyer present." Again, the officer is never going to let you call your attorney, but it establishes you are tired (sleep deprivation can explain many physical characteristics that are often falsely attributed to alcohol consumption), you are polite, and you are willing to take the test (with the reasonable request they let your attorney be present). All of these will be important attributes later in your case. Importantly, despite many officers suggesting otherwise, there is NO legal penalty for refusing the physical tests.
NEVER agree to take the roadside breathalyzer. These are the "alcosensor" machines the officers carry on their persons or in their car (not to be confused with the larger machine at the station after you have been arrested). These handheld breathalyzers are even less reliable than the Intoxilyzer 5000 at the station (which is a piece of crap!). Politely decline the test and don't fall subject to false promises that if you blow below .08 the officer will release you ? he will not!
If the officer still decides to arrest you, which he likely will, the steps you have just taken will go a LONG way towards helping your DWI/DUI attorney fight your case and get you the best possible outcome!