Beware this advice can vary from country to country. In England and Wales for example if you don't say something to the police that you later rely on for your defense that can be used against you e.g. they ask 'why was your boot full of weapons and where were you heading?' you stay silent then later state in court 'it was my brother's car, he asked me to drive it to a friend's house and pick him up, I didn't think to check in the boot' they could perhaps infer you'd taken some time to concoct a false story which is why you didn't answer the question initially however the rules are complex: https://en.wikipedia.org/wiki/Right_to_silence_in_England_an.... You do have the right for a duty solicitor to attend an interview who can advise you on prudent things to say and where you should stay silent.
EDIT: Initially said this applied to the whole UK, actually only England and Wales (from the linked Wikipedia page) uncertain about Scotland & Northern Ireland.