Does anyone know of you can safely install three car seats in a Lexus RX 350? I know some cars you aren't supposed to have two car seats plus an adult or third seat in the middle and can't find anything specifically about this car.

It wouldn't be for long term, but my 6 year old nephew will be visiting and it would be nice to be able to put his booster seat back their with my two kids car seats and just take one car. And making sure it's safe for me to sit back there on long car trips occasionally.