Vehicle: 2014 C300 sport 4Matic, 3.5L V6 - W204.

I initially heard a droning noise for a couple months so decided to take it in to a “german specialized mechanic” I’ve used a couple times for basic oil changes.

After getting the alignment done, the car feels highly unstable. when I brake hard over 100kmh, the car pulls heavily to the right and feels like it’s all over the place. It’s gotten quite scary and makes me nervous to now continue driving the car. Also when I brake at those speeds it feels like the car is fishtailing. The pull can be felt even at 60kmh

Long story short, I took it to a different shop I go to and they said the guy that did the alignment should’ve have loosened some bolts because they were really rusted? They said he probably wasn’t able to tighten so it’s contributing to these issues. They said the issue is the rear control arms and the bushing on the one side is completely gone which is causing that wheel to have a mind of its own essentially.

So replace control arms and bushings? I need to ask them what exactly they’re replacing. And they also recommended a camber kit?

I’m supposed to take it back in this week and over the phone the receptionist quoted me around 600 CAD. 3 hours of labour and rest parts. Sounds a bit high if it’s just for one bushing being replaced. Would the whole arm even need to be replaced?

At this point, basically just afraid that they’ll dk the work and I’ll still have the issues. What recourse is there if they misdiagnosed it after I take the car back? Can I ask them to put it on the hoist and show me exactly where the problem is? They’re a pretty busy shop and always have cars in so I don’t know if it’s okay to ask them to show me like that