Well, I just finished my first Do-it-yourself oil change on the IS-F, and the grand total was $34.51 + tax for the oil and filter (yes I used dino). as well as two one time purchases for about $70.00 + tax for two essential tools.
Since I have not seen any other discussion about doing this on the IS-F I'll discuss what you need to know if you are going to change your own oil on this vehicle.
1. YOU CAN NOT JACK UP THIS VEHICLE
with a standard floor jack, the set jack point is too far for a normal (i.e very good) car jack to reach. If you own a LONG FRAME
floor jack with a 5" or lower lift point, you will be OK. The cheapest I saw one was at SEARS for $499.
2. YOU NEED
12,000lb RhinoRamps or the equivalent to get underneath this vehicle. The 8000lb versions are not as wide and likely less safe. If you already own the 8000lb versions you may try, but I bought the wide ones new and they worked great. You can obtain these for $49.99 + tax at AutoZone. They have a 17 degree incline and this was just enough to get adequate clearance under the front bumper.
3. Once underneath the vehicle the oil pan is easy to access and a 14mm socket will do the trick to get the bolt off. Make sure you have an adequate drain pan, remember the IS-F holds almost 10 quarts of oil. The oil will take a good 5 to 7 minutes to fully drain to a dribble.
4. The oil filter housing resides under a panel that is secured with four phillips head screws, it is fairly close to the front bumper. once removed the housing is easily accessible.
5. I highly reccomend the Assenmacher TOY640 filter wrench (between $17 to $24 + S&H) to remove the housing, it is 64mm with 14 flats and I can tell you IT WILL FIT PERFECTLY! You may be able to get it loose with another tool, but this one worked well and is much cheaper than the toyota/lexus OEM part. BE AWARE that another quart of oil will come out when you loosen and remove the filter housing, make sure you have an oil pan ready.
6. As you probably know we have a cartrige style filter I used the wix part# 57310 for $11.51 at my local auto parts store it comes with a replacement gasket for the housing. I don't know the cost of the toyota OEM part, and I'm not sure if a new gasket is included with each one.
7. After lubricating the new gasket and fitting on the filter housing I placed the new filter in the housing and screwed it back in.
8. Then just add your oil, put the oil cap back on and close the hood.
9. Check your owner's manual for the procedure to reset the service reminder, it has been discussed elsewhere, and it does work.
All in all I was happy with the oil change and it went smoothly with minimal mess. I hope this helps other IS-F owners who were contemplating this task. Please feel free to ask any more specific questions.