I still have several weeks before I return to work, and I'm hoping I'll still be BFing then, which means pumping at work.....and pumping is definitely not my favorite thing. (I had a 30-week preemie with my first and EP for 6.5 weeks before giving up; I hated pumping then, but it doesn't seem bad now that I just do it 1-2x/day.) Anyway, I've read on this board that you can just refrigerate the whole bottle and pump parts together, so you don't have to wash them every time. That's good to hear, but I thought it was a no-no to mix refrigerated milk and fresh (warm) milk, so I'm confused. I'm still trying to think about the logistics of when/where/how I'll pump quickly at work and if I could safely pump while driving on my way to/from work. That would save me a ton of time and stress to have to pump 2 less times at work.
Please share any advice you have in terms of the refrigerating thing and pumping in the car. I mean, really spell it out for me how you do those things.

TIA!
Re: Pumping at work & in the car ?s
I've pumped in the car as well by hooking ponytail holders together and around the pump flange and the other side to my bra nursing hooks. I throw a cover over so no one car see. I just put it all I. The cooler when I'm done and when I get to work or home, I transfer the milk into a more secure bottle.
-My step-daughter is 12 years old.
-BFP #1 on 9/2/12, D&C 10/18/12 no heartbeat on US @ 10 weeks.
-BFP #2 on 1/7/13, R was born on 9/22/13 via C-Section
My routine from months 3-12 at work:
Pump into bottles. 20 minutes, each side. Dump bottles of milk into dated storage bags. Store bags inside of a soft side cooler with 2 ice packs. I used the Lanisoh, double zipper and never had a problem with leaks. I used another soft side cooler with 1 icepack and a ziplock bag to keep my parts cold in between pumps (bottles and pump parts) during my workday. I had multiple pump parts so that I could just throw them in the dishwasher every night. I had enough for 3 days, in case we didn't run the dishwasher every night, but usually we did. I had enough membranes for the week and just sanitized those in boiling water once a week (I kept a small container on the counter and stored them there for the week). When I got home, I combined my bags into bottles for the next day and left any excess in the fridge. When I made bottles the next day, I'd use any excess first and at the end of the week would freeze any remaining excess, which for me, was usually none or very little. For moms with a large freezer stash, they'd freeze any excess and any Friday yield and use Frozen on Monday, to keep a freezer stash fresh.
As far as car pumping, I only did it a few times when I had to commute to our 2nd office and was still driving during my normal pumping time. You'd use a hands free pumping bra, a car adapter, a nursing/pumping cover. You'll want at least 15-20 minutes of uninterrupted pumping time, so I'm not sure how that works with your commute and daycare drop offs/etc. For safety, you'll need to hookup and disconnect while you aren't driving.
To keep supply up, ideally you will pump 3x in a typical 9ish hour workday. For me that was about 9, 12, 3.
Good Luck!
If custodians are unlocking your door, tell them before you return what's going on. Get comfortable with pumping and talking about it
I have a red sign that I hang over the door knob that says DO NOT ENTER OR KNOCK. The kids have asked why they can't come in, and my response is I'm working. NBD
Good luck
I use a second set of parts for second pump at work and if I need to pump on the way home- within about 4 hours.
I usually pour all milk into milk bags so they are easier to keep cool, using less space, in a thermal bag with ice packs.
I pump by holding both with my arm and I use a cover up.
Good luck!