Transmission question 2015 RX350FWD

[wyboojer]

I have owned my RX350 for 7 years. It now has 89000 miles on it and still operates well in all respects. I havent even gotten to where i need the original brake pads replaced even though I have them checked every time i have the tires rotated. My wife drives this car more than i do .Anyway, I'm not  mechanical when it comes to cars and recently i have gotten it into my mind that my transmission may be heading toward a problem. There isnt any real evidence that i can tell that it is slipping and it goes through the gears smoothly. It does feel, however, that when i stop at a stop sign and then start up that it might be slipping a little...very little and Im not ever sure i am right. Also i live on a steep downhill street and when i turn and go down my street , the transmission feels like it is downshifting when i have my foot OFF of the gas. I think that is what it should do but im not certain.

I want to have the trans checked because if it is ok i will keep it...love this car, but if it has problems creeping up on me i will trade it for a newer model. I never go to Lexus dealers because they charge so much for everything and always seem to find something wrong. Im wondering if i dare go to a transmission shop if i can find one to get it checked out instead of Lexus. Im not at all sure there is anything wrong with it and have never had a tranny problem in owning 12 Lexuses. Any suggestions etc appreciated. 

[RX400h]

How often does your maintenance schedule indicate the need change the transmission fluid?

Many modern auto transmissions are programmed to downshift when your foot is off the gas pedal for a minimum amount of time.