The current tear in my outer drivers is on the top of the boot, right under the strut...
Maybe would have spotted a wet stain but I never spotted it...

Anyhow, depending on the tear, the grease generally accumulates ALOT on the rear wheel edges, back of the calipers, etc. With centrifugal force, grease makes it towards the front of the wheel, but by that time....that could possibly mean alot more grease came out then detecting/repairing it earlier.

Go figure but the very minute I noticed grease on the passenger side, I rolled my windows down (hardly ever have the windows done) and I realized it was too late...and would need a new axle.It's around $550-$500ish with a CORE of $50....