Upgrading From My 2011 UL ML to a 2017
 

I'm sad to let my 11 go, but at 14 years old and 215k with mostly original everything, some issues will start creeping up soon; so I'm purchasing a 2017. It's been the best car I've ever owned. I wanted another UL ML optioned car, 2016-2018 in atomic silver, low miles, no accidents, etc. Apparently, that package is still extremely hard to find--I had to fly 800 miles to VA to buy my current one. This one isn't a UL (bummer), but it's the luxury package that's oddly highly optioned. It has the ML and pano-roof, which were the basic requirements and everything but the passenger seat memory, the seat extender cushion (darn), and the semi-aniline leather--just has the regular. The top tier semi-aniline leather in my 11 wore easily, despite cleaning and conditioning. I jumped on it since it only has 75k miles and appears to be a 1 owner that bought out the lease (Carfax said 2 owners, but it was serviced at the same facility for the duration of most of its life). I'm sure these 18's will ride much rougher than the 17's on my 11, which will be disappointing. It's 1000 miles away, and I'm having it shipped since it's cheaper than flying there, taking 2 days off, hotel, meals, etc. I had a PPI done and everything came out excellent.

I'm guessing the 6th gens are just as good or better than the 5th gens, especially with the 3rd series of the 2GR-FE engines. I think the timing cover leak is still an issue with these. Lexus seems to have engine sealant problems everywhere on their cars--valley plate on our LS and GX, cam tower leak on the GX, etc. Any problems known specific to the 6th gens I should know about?

No known inherent issues I am aware of.
But, the transmission, if not services and used hard, can start leaking when the aluminum body of the transmission loses round shape and becomes elliptical. You can look this up by googling u660e weaknesses.

So, don't accelerate hard and keep the transmission fluid replaced every 30-50K miles.

Spark plugs at 100K, coolant every 3-5 yrs, thermostat at around 10 yrs. I also like to replace radiator hoses at around 10 yr mark.

I have a 2018 that I bought with 26K and it now has 40K, so obviously no issues.
It's my family trip car, my fun car is a 24 civic sport hatch 6 speed manual.
Good luck.

I've always had the transmission fluid drained and filled every 40-60k in mine with no issues; plugs I did around 120k, no issues, coolant drain and fill at least once; if not twice. It's been a great car. I hate to sell it, but at 14 years old, 215k, and a 50 miles round trip commute daily, it's probably time. I have my 14 LS460 as my weekend car, and my wife daily drives her 15 GX460. Hopefully, the 17 will be just as good. I wish it was a J vin car; most of these are built in the US now.