Uhhhh...... no.
Heres a little bit further explanation......
I am not sure exactly, but it sounds as if you are asking if you use your hose to wash cars, will your pipes under your house freeze and burst. Just because you use your hose, that does not make a difference in the pipes under your house. Your pipes under your house are filled with water 24/7, unless you drain them, and will not make a difference if you use the hose or not.
Now, if you are asking about your HOSE BIBB.... then that depends on a couple factors. Do you have a normal sill cock hose bibb, or a freeze proof hose bibb?
If you have a regular old school, then that will freeze and burst whether you use the hose or not. That type of hose bibb cuts the water off right underneath the handle, so spigot is filled with water, and is exposed to the cold = freeze and burst. Those are normally the ones you see people buy and place the styrofoam insulators over.
If you have a freeze proof hose bibb, that style actually cuts the water off back INSIDE the wall. So the water in your pipes, are not exposed to the wind and elements. These types will not freeze and burst unless all your pipes under your house do, which is a cause of something else besides the hose bibb.
HOWEVER..... and this is where people get into trouble........ if you leave a hose attached to a freeze proof hose bibb, it does not allow the water to drain from the spigot, negating the purpose of cutting the water off back INSIDE the wall. When this happens, the water is again exposed to the elements, and will freeze and burst the hose bibb. I have seen and replaced these all to often.
PLEASE remember to disconnect your hose from your hose bibb!!!!
Also, a little tid bit of info..... MOST of the time, it is the WIND that gets your pipes and causes the freezing. Most of the water pipe freeze I go on, is because the underpinning of a house isnt tight, or they have not closed their vents to the crawlspace, or something along those lines. Please remember to close those vents during the winter, and keep that air from getting to your pipes.
I hope I explained this well enough. If not, just let me know what your confused about and I will try and explain further.