Fast turn feels like sliding
 

For reference purpose: my previous car was a 3 door Toyota Yaris (which the iQ replaced); my pleasure car is a 370Z. The iQ is brand new with unmodified stock parts.

Whenever I make a moderately fast turn in my iQ (35 to 40 HPM; ordinary road condition), it tends to feel like the rear of car is sliding a bit. Sorta hard to explain in words. I don't hear the tire screech when this occurs, nor lose any traction, so I don't think I'm actually sliding. These aren't sharp turns mind you... just those circular turns like when getting on or off the Interstate. I've never experienced this with the Yaris or the 370Z in the same situation, so it's a weird feeling for me. I'm guessing this has to do with the iQ being so small?

My question: Would getting the sway bar or TRD springs make this "sliding" thing I'm experiencing less annoying?

Thanks for the advice!

I'm sure the rear sway bar would increase your handling performance on the iQ but I've never experienced a feeling that the rear end was sliding on turns.

The poor designs of our seats can contribute to a feeling of instability in turns. If there were side bolsters I think the entire driving experience would feel more stable.

I would say do the mod of sway bar and lowering springs. I had a feeling I was lifting up on turns

Best way to correct suspension
 

The best handling mod you can make for your scion IQ would be to ditch the factory suspension and go with a set of coil overs. In stock form this is a commuter car not designed with performance as a main focus. A much stiffer and lower suspension changes the IQ into an entirely different car. It's fair to say I've done a few mods to my IQs suspension and handling characteristics and I can tell you with just the right mods this car can become very impressive.