The keyless entry portion of it is fairly straightforward but the knowledge is obscure. MB hookups are unique and require specific relay connections that are very different from other applications. That is why it is essential that the installer has experience specific to MB's. The other part of the equation has to do with additional features such as flashing light / horn confirmation. If the installer is knowledgeable about MB's then that shouldn't be a problem. I won't even go near a remote start although I've heard it's doable.
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"