Differences B/t The '06 And '07? Also, December Clearance?

[A-L-E-X]

All,

1) I'm in the market for an IS 250 RWD, with the Luxury package (and 18" wheels), and ML/NAVI option. What are the major differences between the '06 and '07 model? I did a search, and was not able to find anything.

2) Also, has anyone ever purchased a Lexus in December ... during their 'clearance event?' I'm debating whether to purchase one in DEC, or wait until the spring time ... when I get my tax refund, to put a large downpayment.

Any thoughts would be greatly appreciated.

Alex