Lack of cars (and accommodations) at the holidays is a long-standing tradition in Hawaii. Here’s the current rental car status for the 2009 holidays and what I recommend you do for next year.
In Honolulu

The holidays won’t be too jolly, at least in terms of car rentals. The price for a compact car at Honolulu during [...]

Here’s a nice way to escape the cold while not breaking the bank. US Airways is intruding on American and United’s territory, and has sweetened this deal to get you flying.

Airlines: US Airways
Price: $507 round trip (all-inclusive)
Dates:  From January 15 through March 7
Availability: Good
How to find dates: I used Travelocity flexible date [...]