Nope, no searching on either, ferry, you just drive on in the car, leave it in the hold at the bottom lock it, and do whatever the fuck you want lol..
Unless you act very suspiciously, then i have heard of the customs people ripping cars apart, ripping seats out, door panels off, and they don't put it back together for you, you have to stay there and get a mechanic or someone to fix it. Nothing bad will happen though, nobody gets checked, and they don't even speak to you as you go on lol