Have you looked at tail pipe in your ES 350? I looked at several 2008 and 2009 and they all had the same rust problem. If you told you dealer what did they say? I took it into the dealer and they said not to worry! Perhaps so but this is unsightly!
Some thing must be rusting? Do you know what it is? The dealer said bring it in and we will clean it or do it your self since it is under warrarty. What happens after the warrity,and will I have problems. I do not like this fix, even though they said it does not hurt any thing. I do not believe this should happen in a car this expensive and with such quality. I noticed that other lexus have a tail pipe within the crome extension and no rust. What do you think about this problem? and please help me with this problem with what is going on and a fix so I can get this taken in under warranty. MegF
thanks and happy driving.

Condensation if it is rust, especially if you live in a cold climate. I'm not clear on the exact physics but when you turn your car off, you have get cold damp air in a hot pipe. After a little while you've got water beading up like a cold glass of beer. So then you get rust. Unless its stainless steel, it eventually rot from the inside out.

If it is a very soft smooth brown and your in a cold climate it's probably normal.

Regards, PK

Thanks, the end pipe which is not too long has crome on the outside, perhaps stainless steel on the inside. The rust could be coming from the muffler, which I would guess is not stainless steel, so it could rust out after a while? The dealer said it was because the car is in FL where it is humid, however it is in Oh for 5 months in the summer. Some of the other people that had the same problem only had the car in OH for the year. The color is red and not wide spred through the tail pipe so it looks like it is coming from the muffler like a flow towards the end of the tail pipe.
Agin, thanks for your analysis. I noticed you had an RX300, I had two and did not have this problem, and only noticed the problem on the ES350's.

BMW solved this problem eons ago using all stainless steel exhaust system components. You'd think Lexus would do likewise. You'd be wrong but you'd still think that.

This problem is easily solved by using Chrome polish every now and then. Works wonders....and prevents the rust from returning....if used regularly........

Virtually all cars for MAAAAAANNNNYY years have used stainless exhaust. But you have to remember 1 thing, have you ever bought anything from India or China that said solid brass (or some other metal such as stainless) and have it rust like crazy? It probably was made of that metal, but how much of it? I have seen exhaust systems on BRAND NEW cars that have been in some salty water back in cold country when they were loaded for shipment that have a disturbing amount of rust on them. Pure (food grade) stainless is not magnetic (can't pick it up with a magnet) and will not rust. But they can make any composition of stainless they want. The more iron it has in it, the more magnetic it is and the more it will rust. They can't afford to make an exhaust system out of food grade, so it is made of a composition that may rust, but not like iron and it will PROBABLY last the life of the vehicle without RUSTING THROUGH. The mufflers are often Aluminized to prevent the start of rust. Some may actually be made of stainless but probably fairly high dollar cars. Bottom line, the muffler shops are not getting much work today like they used to from exhaust systems rusting through in the life of the car.

Filehorse- read my reply at the end. I'm surprised that Lexus wouldn't use as good a stainless as BMW, but must not or they have downgraded the quality of what they use. High enough quality (doesn't have to be pure (food grade)) and you shouldn't have problems with rust even though it's not pure stainless. It's easy to check how much iron in stainless (such as a screw, bolt, exhaust or whatever.) Just use a magnet, the more the pull, the more iron in it, the less the pull, the purer it is. No exhaust system will ever be pure stainless, but then it doesn't need to be totally pure to prevent it from rusting, for the most part.