Thank you for coming back to me, the fluid appears to be clean and 'nice' red, not brown and burnt and the level appears to be OK too. I don't know if the filter has ever been changed but the car had full Lexus service history up to 70k miles so I was assuming what needed to be done has been done. If gearbox faults codes are read from the OBD-II connector under the driver’s side fascia, there are no faults showing. I also kind of thought Lexus auto transmissions needed nothing apart from fluid changes for the first 100k miles?