Lexigrl

Not sure if your compressor is shot. There appears to be many issues with the system in a lot of older Lexus that have the air-ride. If it is kaput, a new compressor from online Lexus parts is more than $2200 (ouch). One popular thing I've seen is to convert from air to a regular suspension. 

2005 Lexus GX 470 Air Suspension Conversion Kits | Struts | Suspension – Strutmasters

Generally, no, as long as you keep the new tire diameter close to oem tire specs will keep the speedo accurate and the computers happy. 

Maybe this will help

https://youtu.be/_8KvLHrBkf0

It does appear to move too much. 2 out of the 4 mounts are fairly easy to do. the other 2 are a pain. You'll need to figure out which ones are bad. But on a 20-year-old car if 1 or 2 are bad the others aren't far behind. 

Generally, spark plug tubes don't leak, but the round tube gaskets where they seal against the valve cover do. The valve cover gaskets are about $22 each, and the spark plug tube gaskets are around $3.60 each. So parts cost $44 ($22x2) and $28.80 (3.6x8). $72 + tax total, plus any other miscellaneous parts. Your dealer cost is practically all labor. So, if you have a trusted mechanic, I'd get the Lexus parts and have your mechanic do the work.  

Instead of relying on a dealer, there are other sources to get OEM Lexus/Toyota parts as @RX400hmentioned.

Pretty happy with my Yokohama YK740 tires. When shopping for tires, I look at reviews from tire rack and discount tire and filter the reviews to the same or similar vehicle I'm shopping for and also take note to geographic area the reviews are from because road surface has a lot to do with tire/road noise. (For example; I had a new suv in the northeast and rode nice and quiet and moved to the northwest and the road noise was horrible.) 

side note... Consumer Reports isn't good anymore, imho. Their tests are no longer unbiased and will swing to whoever pays them for favorable reviews. 

If you're hearing and feeling a clunk at low speeds while turning (and no noise any other time) it's the intermediate shaft. It's a known issue with the Lexus/Highlanders and maybe other Toyota/Lexus vehicles that use the same steering setup of this timeframe. I had a Highlander with this issue. There is a newer design intermediate steering shaft with tighter tolerances, and I was able to replace it then brought it in to get the steering wheel centered. Took me about an hour and we don't have a lift; just jack-stands. There's no way it should cost what the OP was quoted. 

I put Yokohama YK740 GTX tires on my car, supposed to have 60k treadwear. Coming up on 10k miles for me and so far they've been great.

12 hours ago, Les Lex 2018 said:

Nice looking car.  Are you happy with the gas milage?  My 12 Camry H (same drive train) has a NiMH battery. It met EPA of 41 all the time.

The new ones use the Lithium ion for U.S. cars, but still use the NiMH for those built for Canada.

Thanks.....I bought it used last year and was in really great shape. It's still getting 35-40 mpg's, so I'm really happy with the car. 

I like his video's. They sold me on my current '13 ES300h. Now that he's out with his own shop, just wish he wasn't so far away.

I'd have the tire balance and alignment checked to start. 

Generally, this sort of info isn't going to had just from vin#. The build sheet is where this would likely be found. Not sure how easy it would be to get on a 7+ yr. old car. Good luck.

We had a new Honda that was behaving the same way. Reviewed the tires that came on the car from the factory and the reviews weren't very good. We changed the tires to different brand and the driving experience was way better. See what tires came from the factory and check reviews on them to see how they rate.

https://auto.howstuffworks.com/under-the-hood/vehicle-maintenance/dirty-truth-about-oil-changes.htm#:~:text=More frequent oil changes will help minimize the,a year since the oil degrades over time.

2nd Gen ran from 2005-2013 with mainly facelift changes every couple years, but drivetrain were the same from what I've been able to find in Wikipedia. So, 2008 and 2012 are 2nd generation of IS250 and the 6spd automatic is a A960E

https://www.lexus.com/contact

At the bottom of the page is a phone number, address and a link to send a message. That's a place to start. 

You have to reach out to the manufacturer with the vin#, in your case, LEXUS and get the letter from them. In it, it will list the vin # and in the body of the letter if it is in DOT and EPA compliance, or it will list what is not in compliance. It could be cost prohibitive depending on what is not in compliance and to bring those items into compliance if possible. 

I used KYB complete struts when I had my 2008 Highlander which is basically the same car. We installed them ourselves and then brought in for wheel alignment. Plenty of how-to videos on YT. 

Is there a setting to turn off auto updates?

It's on the Home page and on every startup, it calculates your mileage in a bar graph display. Each bar is your mileage measured over 1 minute and is a running total. All newer Toyota and Lexus have this. I think they did this to have less clutter of info in the gauge cluster driver information center. Our Corolla and Tacoma have the same display.

It would likely cause issues. The difference in diameter is 1.1 inches smaller or 3.3 percent. You want to keep the variation less than 3 percent. Beside your speedo being off, the car's computers likely won't like it either unless the new size can be programmed into the car. Not sure that was possible for a 2007 model year car. Might have to ask the dealer if that's an option to reprogram for different size tires. Whenever I have wanted to change from stock size, I go to discount tire and see what "plus zero" options are available (if any) and go from there. 

Find a similar seat from a junk yard or find a local automotive upholstery shop and get a new seat cover made. Ought to be less than dealer

did somehow the switch in the overhead console get turned off for the doors? my Lexus has 2 switches for dome lights. Some cars have a 3-position rocker switch to do the same functions, but the icons should be similar.

https://seventrumpet.com/reset-tire-pressure-system-tpms-light-on-lexus-is/

Not likely. Sequential turn signals are problematic at best when they're in taillights, so as important as headlights are, I haven't seen any aftermarket ones incorporated into headlights. But more power to ya if you find any.