Full CCTV on the van, built from doorbell parts

The CCTV build is a Blink video doorbell on the habitation door, three battery cameras covering the sides and rear, and a Blink Sync Module 2 with a 256GB USB stick, so clips store locally in the van, no subscription required. It all runs for months per set of batteries, arms from the phone, and the whole stack costs less than most insurance excesses. The full walkthrough is on YouTube: Wild Camping Essentials: Motorhome CCTV.

Alongside the electronics: a Milenco steering wheel lock in warning-sign yellow, because the best security is the kind a thief spots from ten metres and can't be bothered arguing with.