First off...I concur with Lexus411. A detailed car does not mean it is necessarily clean. As I stated, check the trans and yes, do a carfax (which the dealer did). Has all service been done at a Lexus dealership? Make sure you have all maintenance records/they are provided. If it was maintained at a Lexus dealership, this is easy for them to produce.
The financing sounds different than what they told me but it has been a while since I bought mine. However, in November they told me I would get NEW car rates which were 4.99% for up to 60 months. My thoughts are this, if it is CPO they are going to make sure to the best of there ability that it is not a lemon, been wrecked, etc. If you feel comfortable with that price then get it. However, look at what the trade in price is too. For Iowa the trade in price is around $19,000. Thus they are still making money. As I said earlier, I got mine with about 10,000 less miles for $22,988 (Lujack Lexus) so they are not out of wiggle room in my mind...and by the way, that was advertised price, I did not have to spend 6 hours there haggling.
Chuck