Rear top spoiler help

[Dave]

When I took my top spoiler off it had a short length of spongy tape stuck to it. It was the same stuff that's under the lower spoiler

[POLARIS ESCOS]

No it just sits on the tailgate at the top
Only has a rubber seal on the centre support at the bottom

[rs gus]

Should there be anything on here? Is sponge or owt?