Officer asked for Green Card

I am a hispanic female from Honduras, Central America. I have lived in Iowa for quite a few years now and have never been in trouble with the law. Recently on my way home from work I was pulled over by a local police officer from South Dakota for expired tags on my license plate. The vehicle I was driving was a local car dealer's vehicle that I was loaned while my vehicle was in for repair. When I stopped, I unbuckled my seatbelt to reach my purse that was on the passenger seat so I could present my driver's license to the officer. I did this before the officer was at my window. When the officer asked for my license, which I had readied for him, he asked why I was not wearing my seatbelt. I proceeded to explain, but he of course did not believe me. As I was explaining why I had removed my seatbelt the officer proceeded to ask if I was illegal and if I had a green card in my posession. My question to you is, did this officer violate my rights? I was pulled over for expired tags, which I can understand, but the questions he was asking had nothing to do with the reason he stopped me. I presented my driver's license, like anyone else should have to, but why was I asked if I am illegal or if I posessed a green card? I feel this officer stepped over his boundaries by asking these questions. Was this legal?

he can ASK you anything he wants of a legal nature like that, makes me wonder though if he had really gone after you about it and ayou are leagal you might have ahad a discrimination suit on your hands, anyone... anyone?

I found out today that the officer did not video tape the stop and that it is his word against mine. I have heard in the past that most law firms will not take a Civil Discrimination case against a law enforcement agency unless there is a video tape or a very solid witness. If I pursue this do you feel I have a chance of winning?

no

no chance whatsoever

The questions he asks you don't have to have anything to do with the reason he stopped you. It is called pretext stops and is totally legal.
You wanna talk about discrimination? I lived in your former country of Honduras, Comayagua to be exact. I recall being pulled over and had my truck threatened to be impounded because FUSEP liked it. Coming from a country where the cops walk around with assault rifles and have no ethics.
Where when you go to jail if a relative doesn't bring you food, you don't eat.Where a bribe is the only thing that gets you out of having your property seized because the cop likes it for his own personal use.
A country where a fleeing malnourished shoplifter is shot in the back? And where the gringo is constantly harassed by the FUSEP.
You have forgotten where you come from Ma'am.