You will only get raided in two circumstances. After you have raided and if you have something worth/available to steal. If everything you have is behind metal walls they won’t raid you because they can’t get anything. I have metal walls and I know others do too. I leave a few bits in the old car to encourage a raid. Then you get to revenge raid providing you have given them decent enough items. I usually do a near zero durability gun and a few common bits. They then leave the footprints for you to follow and get a free raid on their base.