Hey guys. I got a problem here. My in-laws seem to leave car fluid stains on our driveway each time they have visited. We suspect the stains are oil and transmission fluid and we are thinking about barring them from our home but that's another story. Anyway, the stains were annoying before but after getting more now and in bigger sizes they are downright unsightly. I know there are various products out there that claim to take care of this. The problem is that our concrete driveway is inclined and all fluids eventually run off. Most of the cleaning products seem to work best if let to sit from what I've read. Is there a way to keep fluids settled on this type of driveway? Also, if someone knows of a special product that will REALLY get the job done I am all ears. Thanks.