TOM's RACING Engine Strut Bar
 

Is it compatible to 17 IS200T?

"Engine Strut Bar" is a misnomer. Has nothing todo with the engine.
It is a Strut Tower Brace.
To be effective it must be an order of magnitude stiffer than are the chassis strut towers.
It obviously is not, therefore is strictly cosmetic.
Looks to be a good lifting handle.

I would agree that the naming of the part isn't quite accurate, but that is what the industry recognizes them as.
I would disagree that the bar has to be "of magnitude stiffer" than the chassis to be effective.
The strut tower bar is there to tie the two strut towers together, it is not trying to stop either from moving, therefore does not need to be stronger.
The bar itself only needs to be rigid. As to the one in the pic above, it appears to be one piece with all pieces welded together...without knowing what material it is, I would assume this to be rigid.
The ones that are three pieces: a bar and two plates for the strut tower, would be less rigid on there own.
I would also disagree that it is strictly cosmetic...however, in a vehicle that has double-wishbone suspension it is less effective than if the vehicle had a MacPherson strut type suspension.

now only if the rear uppers looked like this

​​​​​​​Buyer beware!

Suspension guy here ! i am waiting for someone to make one for Gen3 IS350 Fsport, Mcpherson or Double-wisbone, Strut tower does support a bit some car more some car less, my Toyota Solara came with an OEM Strut Bar from Toyota Kentucky America factory, the reason why Lexus IS or ISF don't come with it because the Chassis of Lexus is STRONG and HARD enough, the frame is very very hard i'm also a Bodyshop guy before, i think Dealership nearby heard of "V-Max Auto bodyshop in old toronto stock yard before"

Doesn't hurt to get more support doesn't it ? AWD don't need winter tires but if you have winter tires on an AWD car, does help a bit right ? Cosmetic is call "RICER" cosmetic is when you have Stickers, stupid high WING spoiler like Subaru WRX Sti, stupid Hella-flushed slammed your car on the ground, 1 inch lower than Stock is enough, stupid mods will not increase any performance or power " save $ for Turbo/Supercharge, full header and exhaust system lower the car upgrade suspension etc. (personally i dont think ECU chip mods work) there is no way you gain that Horsepower with that price)