I don't drive a Lexus but have have always been a fan of the Lexus brand. The UX was too small for me and I knew that a new NX was about to be launched.
I drive a BMW X1 and noticed the same type of scuff marks on the B pillar. I realised that a metal button on the back of my trousers was catching the B pillar causing the scratches. I bought some Carplan Back to Black and rubbed some of the plastic scuff marks. I let it dry and the buffed off. Repeated this several times and the scratch marks have disappeared.