Is it a crackling sound or a kind of clunk? Mine acquired a clunking that I could feel in the floorboard while accelerating over a small bump or speed bump. When my Soul was new (less than 1000 miles) I turned the traction control off and popped the clutch. I was on a smooth surface with leaves and some water. I heard and felt the clunk for the first time just then. I took the car to the dealer and had them look at it. The dealer had my car for 3 weeks. They replaces all of the front suspension and finally found a crack in the sub-frame. They reinforced it and welded it back up and I haven't heard it again in 48000 miles. I'm kind of glad I did that. I would hate to have had the sub-frame crack in a collision.
As long as the crack wasn't in a crumple zone, it won't change anythingI tried to refuse the car and they said that is is stronger than any other Soul. I have beat this thing up for 47000 miles after the repair. Twice a week, I drive to up Mt Madonna to work about 12 miles of bumpy dirt road and so far, no problem. I still don't want to find out what will happen in a collision though.