Help Please

Now,im having my callipers changed next week by the dealer who i brought the car of about two and a bit weeks ago..so why there doing this ive paid to have new discs and pads and there paing the abour /callipers cost.

Now my predicerment..i now have a small leak dripping on the exhaust and getting that burning smell...so as its in next week im going to get the garage fitting the parts (not the dealer) to have a look see...but after reading your very informative posts i kinda get the feeling its going to be "transmission output flange seal replacement"...this worries me

I do have a warranty but in the book it says ..
gearbox
"internal gears,syncromeshed hubs,selectors,shafts,bearings,bushs,and transfer gears(excluding oil leaks)

any more ideas of where to look for the leak...