IVA trim is needed to pass the IVA test, it’s essentially a rubber strip with a long edge and a short edge. The long edge goes on the inside of the car or component and you can use a small dab of superglue to secure it. You only need to fit the flared edges on the top wishbones, but I also did the steering rack and lower wishbone hole as well. I looked at going all the way around the top wishbone holes like some blogs, but found it was a bit tight and thought it would be tough to do the bolt up at the front. Unfortunately the top holes are a bit challenging to get right, you have to cut bits away from the back where the frame gets close to the car bodywork.
With superglue just a dab every 2cm or so to hold it in place.
Once I had the IVA trim in position I bubble wrapped the bonnet and put it out of the way in the garage roof. I then secured some cardboard to the outside of the car to help stop any scratches, and put some 22mm pipe lagging from B&Q onto the various bodywork parts to provide some protection while I build the front up.