Dowry demand by groom and family

We are from Chennai, a middle class family. We got an alliance through matrimony site and we proceeded with it by meeting the groom's side a few times. Initially during the marriage discussion that was held at Coimbatore at the groom's house, they said they dont want to demand any dowry (either as money or jewel or anything else) and they would accept whatever is given by my (bride's) parents. Both our parents discussed and decided the dates for engagement and marriage. 5 days before the engagement, the guy's mom started asking for a car. My dad said he doesn't have much money for that as he was taking care of all expenses for the engagement and marriage. he had already agreed to give 35 sovereigns of gold. But he said to the guy's parent that he wants to discuss about this issue on the day of engagement in person. But two days before the engagement, the groom's mom started to corner us saying only if we agree to get a car, the guy would come for the engagement and that if we did not agree to get the car, she would create problems between me and the groom after marriage. My dad was clueless and our whole side had a lot of mental pressure and came up with two ideas, one is that he would get us a car roughly two yrs after marriage when the guy gets transfer to Chennai or he would reduce the gold to 25 sovereigns and get a car instead. He mentioned the budget to be of 5 to 5.5 lakhs for the car and not more than that. They agreed to it and promised no further problems will be created. Engagement happened. Even though I had a lot of things going on in my mind, I was smiling amidst all the mental torture. But the guy seemed really cold. The day after engagement, me and my parents were in hunt for a decent car within the mentioned budget. Went to few showrooms and Shortlisted few cars and we informed the groom about the options but he started asking for a costlier car. I told him to talk about that to my dad as he is the one who is going to finance. He denied talking to my dad as he thought my father would convince him. He could not find any reason and then he started abusing me that I am adamant and that I fight a lot. On the contradictory, he also mentioned that I am not talking much to him and that is hurting him. While the truth is, I have had a very decent conversation through Whatsapp everyday and I have all the backup of those conversations. There was no fight or adamancy whatsoever. He finds reasons to blame me inorder to stop this marriage but he also mentions that he has no guts to take decisions (negative decision) as that would favor me in rising a complaint against him. We have already fixed the hall for marriage for which it cost a lot of money and also the engagement expenses. He is cornering us again after the engagement so that we would do anything they ask for fearing our reputation and my future. I want to file a case on him and his mother for all the demanding, abusing, cornering and mental torture that they have given us so far and for they are backing off now. And I want to know will it affect any of my future alliance. Do we have to wait till this case gets resolved in court, to see another alliance or can we proceed with the complaint copy alone? I have all the whatsapp conversations between me and him, he is afraid to talk on call as he thinks I would record it and use it as an evidence.