Honestly, there is no limit to modifications if somebody wants to customise his or her car. However, not all car modifications are permitted by the law
I can understand your query, let me give clarity on 3M pricing. Actually 3M original will cost you more than 3500 for hatchback. In market there are more Fake 3M tints available. The price will be cheaper if you are going to take a fake 3M tints , if you are looking in a budget go for a Garwarre or wurth brands tint.If you are going for a 3M kindly cross check with the shop keeper.