So dealer tells me my front brakes have 5% and rear 10% left. What exactly does that mean in terms of how long I have before the pads are completely gone? I have 20K miles, drive the car on average 75 miles a week only on the weekends. So with those numbers, how much time I have before I absolutely must replace them?

 

a month or two.

 

Hard to say without knowing what they base the % out of.

Generally, pads have about 10mm of material in them. It's recommended you swap them out when it goes down to 4mm.

Literally speaking if they say you have 10% pad left, out of 10mm, that puts you at 1mm - which is ridiculously thin.