Thanks for the reply.
I don't use CM to install mods; I do it manually.
I needed to delete the newly installed Cars and Tracks folders as a lot of rubbishy Kunos original car skins (that I had deleted) were reinstalled (Sounds too, tyres... ), and to some extent this is true for the tracks too.
On my Windows 10, when you delete huge amounts of data (like 100Gbs or something), a warning comes up to say that it is too big for the recycle bin. Also, I deleted the recycle bin contents after the integrity check - there wasn't much in there.