I can only speak to California law specifically, but the fear of causing yourself more trouble if you don’t let an officer search your car, house, perseon etc. is the wrong fear to have. It is your right to refuse to a search.
This is because an officer at that time is seeking permission to search through asking for your consent. You do not have to give, and shouldn’t give your consent because you never know what they can find, because there are times you don’t know who, or what was in your car prior (even if you believe you have nothing to hide).
This comes however with a big caveat, orders. There are certain orders you cannot refuse, such as an order to step out of your vehicle. This is because it is a lawful order, not a request and by law you have to comply. It is difficult to know when something is an order and what is a request, and many people would caution to follow any direction an officer gives them, however the better thing to do is calmly ask the officer if it is an order when you are unsure.