My MB Dealer is offering to install parking sensors on a 2015 C300 I'm looking to purchase. They mentioned that I will get the beeping sounds but no visual indicators. Any advice/thoughts?

Thanks!

"Offering"? at no cost? First off, I would look for a MY16 instead.

It costs around $10 on ebay and you can install it yourself. Wire it to the back up light. That's what one of my friends did on his Honda. It's been working without issues for a few years now.