Just keep watching. Rates were really good a week or so ago but seem to have gone back up this past week. Currently I have a rental from
Alamo for 6/8-617 at $172 all in and National for $202 all in. (I'll make a decision as it gets closer) I can't duplicate either rate this week.
I hope as it gets closer rates will go back down. I know the May car rental thread had some smokin' hot deals so I'm hopeful for June. There is a June car rental thread you may want to watch.