That small amount of time is easy to get, just running in, & out of your car, While you are in the car etc... You don't really have to sit in the sun.5 to 10 minutes without sunscreen is all you need. Get the rays between 11:00 am and 2:00 pm. And you don't even have to expose all of your body. Your arms are enough.
I hate sitting in the sun even for 5 minutes. So I get my Vit D year round through pills. I take about 5,000 iu daily during the summer, and increase to 10,000 iu daily during the fall, winter and spring.