You [a hypothetical poor person] don't have a car to get to a supermarket...
70% of the poor own a car, 25% own two cars.
When you are poor, you don't have the luxury of throwing a load into the washing machine...
64% of the poor do have that luxury.
http://www.census.gov/prod/2008pubs/h150-07.pdf
It only gets worse from that point on. The poor can't get free supermarket discount cards?
Those particular numbers don't tell the whole story.
There are many ways to "not have a car", including "the car has broken down and they don't have the $300 to get it fixed, just like what happened last month because the car is fundamentally unreliable after owning it for 15 years (or getting a 10-year-old used one because they had a windfall one month, five years ago) but they can't amass enough cash to get another one, because they're living hand-to-mouth."
http://www.ers.usda.gov/Publications/EIB59/EIB59.pdf
Some quick math suggests about 30% of poor people live in nonmetro areas.
http://www.ers.usda.gov/Briefing/Population/
Since you seem unwilling to browse any sources I cite, I'm not going to bother looking up suburban poverty.
If you are interested in understanding poverty in the US, you should skim that 642 page report. It's a fantastic report and it answers many questions one might have about the material conditions of the poor (and many other categories of people).