So, where do we start.... 1• The Donkervort D8 GTO doesn't have a Rear Spoiler (Wing), it doesn't come with a wing from the factory. This looks to be some low quality ripping attempt from one of the Forza games most likely, as the Spoiler (Wing) is from the generic Forza Horizon car upgrades menu. 2• The Mercedes-Benz SL65 AMG Black Series sounds like it is equipped with a V8 and not it's unique sounding Twin-Turbo V12 that makes it stand out. Yet another low quality mod, and I am sure I had a similar sounding mod around 5-Years ago...... So not much progress in the areas that matter. 3• The Porsche 944 Turbo S is about as loud as a Nissan Leaf, completely unrealistic sounding once again. Just because it hasn't got a huge V8 doesn't mean that it is quiet, in real life this car has a lovely note to it so yet another car where no effort has been put into it's sound. In my opinion these three cars aren't worth adding to your mod collection unless you enjoy having to go back later and purge out old rubbish once something genuinely nice comes along.
The wing and frontsplitter on the Donkervoort are optional. Only on the first skin by default (out of 10 skins). In the UI and extension folder is instructions to remove those parts (as simple as deleting 1 file). Therefor your comment seems to suggest you din't try it before judging it? Would love your feedback after you've tested it yourself. It's my first mod, so I can still learn a lot.