She sneaks in at night, using an ungainly-looking contraption of poles and springs strapped to her legs to carefully skirt over the barbed wire, sticking to the far corners of the junkyard. She never enters in the same place twice, and doesn't go to the same junkyard more than once a week. Not a great way to get materials, but she really wants to lay low until she has something Hero-worthy. Excessive dumpster diving is suspicious too, alas. She keeps her flashlight pointed at the ground, gyroscopically stabilized and hanging off her shoulder.
...Cracked cylinder heads. Useless. The timing belt could be good though. Transmission's shot, meh, but some parts can be salvaged if she's quiet about it. At least it's not an electronic transmission - her power hates those for some reason. Battery is fried. Junk. Door rail and rollers - could be good, but it'd be loud and take a while to take the door apart. Come back if she doesn't find much. Ooh, an old soda machine! Pressure valves... Seals gone, but otherwise good. Lots of tubing to go with it. Condenser looks almost new. Score! She starts stripping it down eagerly.
She'll be busy for a while, possibly visible to any other people who are going around at such a late hour.