Originally Posted by zlc
Losing a year's worth of interest doesn't make a whole lot of sense, even with you best case scenerio, you are talking about $0.03+ for a point/mile. However, if one can make an estimated tax payment right now for 2005, then wait a month to file the return and getting the refund back, then no losing of interest, and cost of $0.012 per point may not be a bad deal.
You have complete control over your W-4. You can start taking out less in taxes now and make the estimated payment at any time during the year. As long as you meet the appropriate test (and you must be careful), you can always get your miles without any lost interest.