buzzing / pulsing at idle is the low pressure fuel pumps, located under the driver seat. Does the buzzing come from that area? If so, it wasn't recalled as mentioned above, but there is a TSB on it to re flash the ECU with updated parameters which worked for me and many others.

I also get rattling from the sun roof area, i find it to be underneath the paneling surrounding the sunroof vs coming from the glass area itself. No fix found - annoying af

 

Thank you for the feedback. Yeah it seems to be in the drivers side area. I’ll have them look at it.

The moonroof is quite a mystery. I was touching every part to see if there is any wiggle that would make the rattling sound...but everything’s right as a drum. Very annoying...

 

The RSR springs are off!

Car handles much better. Not as jittery. Also notice it’s dumbed down some of the rattling on the moonroof. No more clunking noises too! Car feels right. I love it.

Now will just need to change to MPS 4S.

*Also good to know my shocks are still in good condition. No leaks.

 

Glad you got the RSR off. So I guess, I was right? LOL

It will get much better once PS4S tires replace the lion something tires.

 

If anything I can stop scraping on my steep driveway.

Usually lowering springs are advertised to lower center of gravity, improve handling, etc. but going back to OEM really settled the car to the way I like it.

 

Lowering springs are mostly for show and a cheap way to lower the car. They rarely ever improve handling of a car that already has performance oriented suspension. In order to achieve the lowered ride height so that it could settle, they end up sacrificing springs rates compared to the OEM, which results in blowing the OEM shocks because they are not valved to handle so much work. For the RCF, swift springs are the only ones I have seen have good spring rates that can work with the OEM struts/shocks, but they only have a 0.8 inch drop.

I have been burned by the Tein S-tech lowering springs I put on my Corolla XRS back in 2006. I blew all 4 shocks because they had a 2 inch lowered height, but handled like cr*p. I ended up going with Koni yellow adjustables (set to full stiff) and matched the Megan racing springs with 1 inch drop, which ended up being a good combination and still are working today.

The proper way is to go coil overs to improve over the OEM as it gives more adjust ability options

 

And there's even more to it when you consider roll center, instant center, roll couple and roll axis just to name a few things that all change (and often not for the better) with lowering. It's foolish to assume a fashionable lowering is actually going to improve performance, especially if you measure it with a timed course.