I need some expert advice from legal points and also personal

I(29yrs old) was working in Solarwinds, a software company in chennai for some time. One day suddenly a good looking girl sits opposite to me. We got attracted to each other and I made a marriage proposal . She discussed with her parents and she soon fell in love with me. We were in relationship while working in same office . On one friday, I finally choose to take her out for dinner right after the office hours. We had a nice time and I dropped her home that night. Monday I get a call from my uncle in my hometown , Madurai. This is the car I use it when I am at home town. And I was using this car completly during my 2 weeks vacation before few weeks in madurai.His Nano car was smashed into pieces, completely torn off . This happened Sunday midnight at heart of the madurai city. My uncle calls me asks whats is happening. It was a shock for me and also my girl friend. My girl friend had confessed everything about her past, a few highlights, she had 2 past relationships and all two physical,her dad and family fled from madurai some 7-9 years back , because he had filed a IP after heavy loss in business. Me and my girl friend started listing out the possible suspects , from her side,was it her ex-BF's ,from my side, was it some one in my office because there was lot of jealousy and rumours in office when we were in relationship ? Finally FIR was filed by my uncle in Madurai police station. After lots of enquiry the police was not able to find the culprit as there was no clue. The police does not know my side of story, which could have been something to investigate. Simply because I did not own the car, my uncle did not highlight my relationship to the police. During police investigations, they did mention that these incidences happen if someone had along term enemity (which my uncle did not have any one), during relationships (where the Ex is furious to know that the girl has moved on and has a new BF or different scenarios) . Me and my GF then moved on in relationship and we started going out regularly. She was pushing me to get into physical relationship soon. We started going to out stations on trekking, we went to coorg and Nandi hills resorts, we stayed for a day and yes we made love to each other. After some time, my parents were not happy with my GF. My parents said a no to this marriage. So we split and broke up. That was the most terrible thing for me and it was very difficult to overcome. I asked my girl friend to even come with me, as we are majors,independent individuals and we can get married, a several times. But she was hesitant and she did not come. Now she is going to get married. Is there e way I can file a case in the court to get a confirmation that this part of life of hers is being shared to her new BF or the guy whom she is getting married to soon. The reason being ,the culprit who broke the car is till not found by the police. The person who broke the car seems to be a bad guy. This can be a serious threat to my life or hers, any time in the future. 1. I want a legal approach to her new BF, to know about the girls past and the relationships in detail. 2.I also want a legal approach to her new BF, to know about the car incident and what kind of threat it could lead to in the future to either one of us.(all three of us). The reason is, the person who broke the car is a bad guy. He is till not in hands of police,he is living a normal life and confidant life. He can be a threat to anyone of us in any forms. On personal not, i still love this idiotic girl. I want to marry her. How to get her there?