I have had the CEL and VSC lights come up a few times on my Wife's RX350 a few times. The first time I took it to the stealer, and they charged me $80 to clear it and tell me that it wasn't covered under engine warranty, and sometimes they just pop up for no reason.
So this time I used a reader ( available for $80 ) and read code P0354, Ign coil D. With a little googling, I found that D is the front center coil.
Ordered coil online for $45.
Now the best part, the how to:
1) Pop hood and remove engine cover. You simply grab on to it and pull it up. It just pops off.
2) Remove new part from box, so you know what you're looking for.
3) Locate problem coil.
4) Use 10mm socket to remove the only bolt on the coil.
5) remove wiring connection.
6) replace with new part.