Hi there
As I see it, no one has installed on the audio system Mark & Levinson an USB adapter.
Well i did it personally so i would recommend it to all members who drive a RX400H.
The Y cable needed around 25 euro :
https://www.ebay.com/itm/Y-Adapter-Compatible-with-Toyota-since-2004-MP3-CD-Changer-Satnav-Radio-Small/191969914080?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
Electronic box needed around 55 £ :
https://www.ebay.com/itm/Yatour-USB-SD-Aux-MP3-Adapter-for-Toyota-Lexus-Corolla-Avensis-Highlander-Car/284110172516?hash=item4226493164:g:WhcAAOSwbd5eqVa-
I did the installation myself, so I didn't need assistance.
On the other subject, regarding the petrol consumption / 100km, I mounted on the RX400h LPG system, so running on LPG I cover 100km(62 miles) with 5.5 £, that would be around 8p/mile.