Alibaba for some reason will not sell to me. This is by no means an endorsement for anything other than browsing in fact I would go with a reseller often like DMP for your Screens.
That being said. Checking out Alibaba and entering your common model code and year can help give you an idea of what kinds of mods will be available on the secondary market.
You may want to include other world wide designations or commmon descriptions as seperate searches. For example using both C218 & W218 in separate searches will likely uncover products that just one of the searches won't reveal.
Facebook Group Posts Are an Awesome Way to Find Body Kit Mods.
Sponsored Group Posts are a source to consider facebook to find and discover what may be available. For example there may be a sponsored post where you can direct order carbon fiber parts or a custom lowering module.
Member Posts on Facebook Groups is a Holy Grail like source of finding inspiration for your mods.
Members of model specific mercedes facebook groups often post pictures from across the world, of their modified cars. Here is an example of such a Mercedes Group for the CLS. Perusing these pictures can help you find ideas on how to modify your specific mercedes benz. More over, you can often ask directly or thru comment where modified parts were sourced, and if there are any drawbacks, installation advice etc.
Some Modifcations themselves have their own groups
Mercedes Android Screen Owners should check out the group "10.25" Android Screen" on Facebook. There are links to the discord, and notifications of firmware updates. Some Super members like Nick C. produce awesome firmware revisions that aim to satisfy the persnickety owners of modified Mercedes owners, who have taken what is arguably the best car built and decided this is good, but let's pursue my definition of perfection and upgrade it to a tailored specification.