Coming back to this... I went through this exact same headache when I first got my IS 500. Honestly, I didnt want to blow a thousand bucks on a setup ...

Youre right to be cautious about the fitment. The 4xe floor pan is definitely different due to the battery, so standard gas WL mats wont sit flush, es...

Huh interesting. I had no idea. The more you know I guess 🤷