coolant leaking : Very weird senario

[yeuchau]

Ok, so 2 weekend ago I noticed coolant on the garage floor and I pop the hood and can see that coolant in reservoir is actually slightly lower than the minmium level, so i fill it up to somewhere between min/max and drive the next day and notice coolant on my garage floor again (still above min level, this is last Wednesday), so I took my car in to to flash the car back to stock (had S2 tune before). Note that the car is not overheating.
While they were flashing the car, we pop up the hood and can see coolant behind the lower radiator area (where the water pump area is) so we suspect that it could be water pump.
So i've been monitoring my coolant level and garage floor and haven't notice any sign of leaking (coolant level on reservoir has gone lower since remove the tune) since i remove the tune last Wednesday, a week passed by now, everything is still normal.

my intention is to flash back and take it in for warranty repair, but it's not leaking anymore, any idea what could be the issue?

Note, my car is currently in dealer (as of this morning) for that passenger seat sensor recall, but i didn't mention the coolant issue to then (I didn't want them to scan the car), i was hopeing they can see the leak and just replace it without scanning the car, but it's not leaking anymore for past week.

Anyone had similar behavior before?

[Brooklyn]

Only thing that comes to mind is a rock damaging the radiator, but that wouldn't explain why the leaking has completely stopped, unless the hole was small and has somehow become plugged.

[yeuchau]

I highly doubt it's rock, also I don't see any visible damage.

[yeuchau]

So, they didn't see the leak initially , but I end up calling service adviser and told him I see some type of pink fluid on my garage floor and wasn't sure what it is. He said that must be coolant, but they don't see anything obvious. They end up doing pressure test and found out water pump was leaking(very little), but was one time leaking more, hence they replace it under warranty (no TD1)

[eveleth]

Yep, just had my water pump replaced on my 12 A6 at 40k miles. It was leaking out gradually on my garage floor and once they pressure tested it at the dealer it spewed out all over the shop floor.