I have some rather hard L/P tires (bone rattling ride) compared to wifey's Yaris HB and I've read some threads about lowering springs that made the ride SOFTER THAN STOCK. Is there anyone out there that can tell me where they acquired these springs and what brand/part# are they, or if it's even possible.

 

I wouldn't expect to find any springs that are softer than stock. You're better off looking into more comfortable riding tires. Or if you want to drop down to 15" wheels, a taller sidewall tire will give you a bit more comfort as well.

 

I'm also interested in this. I have 215/35/18 tires, and the ride is pretty rough. I also picked up some stock steel wheels, The ride was much better, but I didn't care for the look so I switched back.

You could try changing the shocks and struts to the Monroe Sensatrac. I've heard good things about them for the Scions.

 

if you want a softer ride than stock, try using TEIN S-techs.
im on them, and their say "soft", but it also offers a huge drop. I have a finger gap between tire and fender.

 

It's one of the sacrifices you make when you run less sidewall unfortunately. I'm on 15's and the ride was quite soft and comfortable before I put coilovers on and put the car on the ground., Your options are pretty much to find a nice, softer sidewall tire (not always a good thing depending on your roads' potholes and such), or get something with a bigger sidewall/reduce the size of your rim.

 

There is your problem, you are running a 35 series tire...That is a rubber band and the ride is really rough...I'm running a 225/40/18's on Tanabe DF210's and the ride is not bad...You could run TRD springs and a 225/45/18 series tire and get away with it because the drop on the TRD is minimal...Might throw the speedo off a bit more though...