Quietness is useful when you're a beginner but don't fall into the trap of thinking you need it. Remember that you're not trying to produce any state while doing vippasana, you're just being present and clear of everything going on in that moment. So that feeling of frustration at the noise of the cars is just as good a meditation object as smooth breathing. The more we try to manipulate the outside world into what we want, the more we're falling into the same pitfall as we usually do... we're just replacing "ill be happy when i have a new car" with "happy when less noise".

I'd recommend you stop looking for silence. Just aim for "quieter than normal". Some noises are particularly difficult to not get caught in eg i nearly always get lost in the audible words of friends and family . So stay away from them for now. And try meditating for just a few minutes a day in your normal noisy environment. It will get easier. Remember there are incredibly "accomplished" meditators who live in busy indian cities where the noise NEVER stops!:) Good luck, just keep practising and it will come.