Possible Rear Swaybar Upgrade Alternative - 16'-18' Lexus RC?
 

I'm looking into an upgrade alternative for my Rear Sway bar on a '17 Lexus IS200t. I read in another post that the Lexus RC200t/300/350 may have a larger rear sway bar that is backwards compatible to our 3rd Gen IS. Both models are based on the same platform. I'm hoping our forum/suspension experts can clear up some questions and confusion for me. Thanks in advance for sharing in your knowledge.

1) What is the diameter of the stock rear sway bar on the 17'-19' 3rd gen IS vs. the 16-18 RC sway bar?
- I recall reading that it's a 3mm difference (14mm vs. 17mm).

2) Is there a diameter difference between the 14-16 (Pre-facelift) vs.17-19 (Facelift) Lexus IS models?
- I know that the facelift 17'-19' IS received updates on certain suspension components (GS suspension update I believe???). I ask because I noticed Pre-facelift IS250s had different brake calipers and wonder what else could be different.

3) Is there a difference between the IS Base Model and F-Sport rear bar diameter?

4) Is there a difference between the IS200t/IS250/IS300/IS350 bars and did optional packages include Sway bar upgrades?
- I know that the IS350 F-sport has the optional active suspension available.

I found different part numbers for "Rear Stabilizer bars". The part numbers are confusing me and would like some confirmation before purchasing.
- Lexus RC/16-18 IS Rear Sway bar Part number: 48805-24040
- 2016 Lexus IS Rear Sway bar Part number: 48812-53050

Reference Links:
Lexus RC Sway bar forum post
Lexus 48812-53050
Lexus 48805-24040

Bump. One of the members did confirm positive results with part number 48805-24040 though, planning to do that before winter. @webra

LexusPartsNow.com shows that same part number for the '16-'17 IS350 RWD models, so I am confused how the RC350 bar can be bigger?!?