Late on a Friday evening I was at a 7/11 kwiki mart in MA. I bought 2 sandwiches, and a drink and was paying for the the purchase at the register when 3 police cruisers pulled up.

The officers entered the store and inquired if the the silver ford taurus outside was mine. I answered that it was. They ordered that I step outside the store immiediatly and take a field sobriety test. When I inquired why I was being taken outside, they answered that there was an eye witness account of my car driving the wrong way in a nearby highway.

I explained to them that it was not me and that I had not driven on that highway at all that day. My keys were in my pocket, my car was off, and legally parked. Regardless, they took me outside and demanded that I take the nine step turn field sobriety test. After that one test, and not requesting any others, they asked me to take a portable breathalizer, which I refused.

They arrested me on the charges of OUI and Driving to endanger. When I was brought to the booking station, I once again refused to take the brethalizer, which means an automatic 180 day suspension of my license. I spent the night in jail, and got my car out of tow the next day.

Is this legal? I was not observed driving by the officers, was not in or near my vehicle, was in a private establishment and was only given one field sobriety test.

I did hire a lawyer. Based on your experiences... what will be the result of my situation? Was this a legal arrest, did the police officer have probable cause?
In reponse to a few answers:

1) It was at night
2) It was not me who was driving the wrong way on the highway, of that I am certain.
3) I was advised by my friend who is a lawyer to never take a breathalyzer if you have had anything to drink in the past 6 hours, as a reading over .08 means an almost automatic conviction.
Making negative assumptions on my character or rude remarks like "get a bike" are unnapreciated.

Thank you to those law enforcemnt officers who are answering this question in an informative manner.