If you are going to do all repairs and maintenance yourself, then very likely you need Star Diagnosis or, at a minimum, a Foxwell NT510 Elite diagnostic tool.
I just purchased a 2004 Mercedes Benz Sl55 a few weeks ago. I’m planning to do all the maintenance myself ,along with some light mods along the way. (pulley, headers, exhaust, cooling, etc).
I read this article: Foxwell NT510 Elite Benz R230 350 SL 2005 review. (From unboxing-> Initial Background -Setup -> First Use and maintenance function review.)
I decided to buy an NT510 Elite. I am glad that it basically meets all my needs. If you also have DIY ideas, I recommend it to you.
Important using tip:
Foxwell NT510 Elite scanner needs to be registered through the Foxwell site and then you download an “update installer” to your computer. The Foxwell then connects to your computer to download software and install the Benz specific stuff.
if you’re an Apple user, please note, if you want to get one of these you will need access to a Windows computer to initialise the Foxwell.