When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
You need to do a lot of measuring yourself to figure this one out. The IS is a lot smaller inside than the RX.
You also need to check the seat mounting bolt locations on both seats. How far apart are they in width and front to back.
Do they mount in a similar way or location.
Do the inside seat belt stalks mount in the same way? You may have a seat belt compatibility issue or mounting problem.
You cannot drill more holes in the floor for seat bolts, they will not be reinforced and it would not be crashworthy.
Then there are the issues of wiring the seat controls. Do they plug in the same way?
I think those are sufficient challenges to keep you busy for a while, or discourage you from doing this.
Why do you want to sit that low in the RX? It defeats the purpose of the vehicle, may make it hard to see and it already has seats with height adjustment.
Yes you are right a lot of difficulties. At first I thought that the size is the same and if I leave the bottom, then the upper part can be connected to the original one from RX , also the slots should be the same ( Toyota). if ventilation is excluded. Loved the color and leather. But.... Long time ago I inserted the seats from the Passat to Jetta WW leaving the original lower base. Thank you for answer.