If you buy e.g. a pack, but you don't want to have a track or car installed from that pack, it cannot be done, it's "forced" to be installed by design. That piece of content reserves 2x the disk space it represents because an .rfcmp file is stored in your workshop folder, and the content itself is unpacked in the installation folder. It's been like that since rF2 moved to Steam. On a side note, uninstalling the .rfcmp file without unsubscribing from free workshop content forces the download of that .rfcmp file, despite you having it unpacked already in your installation. Just saying so nobody tries itThat's ridiculous, so I already own Sebring and if I buy track expansion budle I will have 2 copies of Sebring on my HDD?
Without offering discounts on individual items S397 is gonna bury itself. With the amount of conecnt atm it's still bearable but few years down the line when people realize they have to spend 150€ to play online it would be a huge deal breaker.
Regarding what you asked, I did not know how it works, but John-Eric explained it nicely