After having the struts replaced the suspension is still squeaking when driving over a bump

It's hard to say without being there to witness the noise, but what I can say is that these cars usually get struts and control arms at my shop when they come in for suspension noise.

Hello, I'm Danny.

There is a possibility that maybe your noise was misdiagnosed. Having 170,000 miles on your car does lead to a lot of noises and squeaks but your car should have been put on a vehicle hoist and had a thorough inspection first. Both struts and control arms with bushings are an item that does wear with time and mileage. To answer your question, no you cannot grease or use lubricant on a non-serviceable control arm that would be a waste on a worn out part. Yes, you can buy replacement parts from Ebay or Amazon etc. To save money as long as you purchase a correct part for your car. You can always buy a replacement part from your local auto parts stores like Pep Boys, AutoZone, or O'Reilly's for a discount as opposed to a shop or dealership. Finally, yes your car might be noisy until the problem is actually fixed possibly being the rear control arms. It's possible struts may not have been the noise. I've attached a picture below of the bushings in the rear control arm that I'm speaking of and circled said bushings in red. There are 4 control arms in the rear of your car 1 upper and 1 lower per side. Hope this helps and thanks again for using 2CarPros.