I'm looking at trading/selling my 2004 Tacoma and Carmax made me an offer. It's about where I expected the offer to be from a dealership. My current truck, with low miles, tends to fetch a premium from a certain demographic of Tacoma fanatics. I want to test the market and sell locally for more money but if it doesn't work, I'll probably go back to Carmax and just be done with it.
I can't imagine their quote would vary that much after a week or two. Anyone received a 7 day quote, waited longer than 7 days then gone back for another quote?

I would think it would be very close. BUT, you never know, it might be 10% higher (or lower) the next time you go depending on their inventory, who's appraising it, etc.

Yes after about a month but I also put about 2,200 more miles on it. I also took off the hitch, all weather mats (put factory carpet back on) and rain guards off. Ended up being about $700 less than the first offer.

But this was for a Hyundai Tucson, not exactly a rare or in demand vehicle.

Go back in the first week of the month. They will offer more because they will b confident in moving your truck before the end of the month and avoiding any taxes due.

I believe they just run it through their system again and adjust for mileage. When I took my truck into Carmax for an offer and they also ran it through KBB based on their inspection, KBB offered $1600 more than Carmax. That offer was only good for three working days though. You can run it through KBB yourself and take it in to a trade-in dealer if their offer is acceptable. Closest for me was a Ford Dealer.