“Hi Mark,
Thank you for your reply.
You are absolutely fine to fit roof bars to your RX with a sun roof, providing there are t-tracks for them to fit to.
However, you will need to check the vehicle hand book to see what the roof loading limit is, with the sun roof, as this will be less than a standard roof.
You would then need to take in to consideration the weight of the bars, the weight of the box and then the weight of whatever it is you are putting inside the box.
Best wishes,”
Will check my manual when I get home from scotland but I suspect with it being JDM there might not be anything specified.