For the most part, getting rid of our car has been a lot easier than I expected. I don't miss it much at all. There are a few hard parts. Getting the kids to doctor's appointments can be a challenge. And gardening tasks can be tricky without a car. And I do a lot of gardening.
The trailer helps a lot. The other day I was able to transport these tomato seedlings to one of my garden projects (a really fun shared backyard garden). We started these plants under lights in our basement (a little too soon) and grew tall and leggy. They seemed to handle the ride pretty well. I rode carefully and none of the plants broke. I used the cart for pepper seedlings, too.
I had to rent a zipcar pickup truck to haul salt marsh hay bales (for mulch) and also tossed my cucumber seedlings in the truck. They did not like the pick up ride (or transplanting in general).
Gardening can require a fair amount of hauling of heavy, bulky material, and a car or minivan definitely makes it easier. Still, we've managed pretty well even without it. And I'm getting in great shape from riding to all the different gardens (they're pretty close to home--the farthest is about 3.2 miles round trip, but up a pretty big hill on the way there).