Firstly, let me say I fell in love with this beautiful looking car, which has refinements and a quality feel. However, I advise that you look carefully at several issues before buying.
Offset pedals - Look down and the clutch is almost in the centre and not the left. This can lead to hip/back discomfort. The taller person that can move the seat back further may not have this issue. There are articles online that confirm the Lexus IS 220 has offset pedals.
Economy - The diesel engines have been changed/modified at least twice over the last 2-3 years in order to improve economy. Beware although latest models claim close to 50 mpg combined, 2008 and earlier models will do well to give you 40-45 mpg combined. Drive hard and you will struggle to get 40 mpg.
High gearing - No power at low revs and you have to regularly drop down gears to get acceleration unless revving hard. The 6th gear is only usable above 80-85 mpg and it has little torgue even then so is not really something that is of any use in the UK. This means that you have to stick to 5th gear, which leads to poor(ish) economy at motorway speeds. Excessive gear changing ruins the driving experience.
Loud crack - As stated elsewhere on the forums, I periodically heard a loud crack from the dash or windscreen. Annoying more than anything but have never come across this before in any car and I have had quite a few.
High idling - When cold, engine runs very fast for a long period of time. Annoying.
The Lesson - Forget the brand, go with your gut feeling. Too many issues for me and the Lexus is now history. An expensive lesson!
