While cleaning my 2010 RX350 I noticed rust build up on subframe next to both rear wheels, underneath. I leave in Ontario and this winter was particularly harsh, lots of salt was used. Has anyone noticed this much rust? not sure what to make of it (see the picture)

 

I'm in N.B, another rust prone area.
At this point it looks like nothing more than surface scale.
We try to get ours washed on a regular basis at a spot that has the bottom spray.

You might consider getting it to a rust coating shop, Rust Check comes to mind.
Won't cure it but will stop it.

 

^^^ +1 on the Rust Check. When I rotated my own wheels this weekend, I noticed some superficial rust on the suspension components on my '13 as you show (but a little less) and I got my trusty red can of Rust Check I bought at Canadian Tire and gave it a spray. Looks almost new again.

 

I noticed some rust on my 12' bottom as well last week when I crawled under the car to install a hitch. Curious about how severe this was, I also checked the belly of my 02 Camry. I was surprised that not much rust at all was found under it. I don't think my Camry was rust proofed when I bought it.

Just my small sample observation.

 

Thanks for responding. I also have 2007 ES350 which less rust compared to the 2010 RX350, must be the quality of metal/finish used in recent years. I do like the idea of coating it with rust check stuff, maybe after every winter.

 

For ~120$ a year, Rust Check is worth it if you plan on keeping the RX for many years.