Hot smell !

It makes an especially bad smell if grease from the axle joint leaks onto it.

what do you mean by "hot smell"? (strictly speaking, temperature doesn't really correlate to a hot smell...) - I have had people describe everything from antifreeze to overheated brakes to burnt clutch to burning plastic as a "hot smell", so I am not really sure what you mean.

Hot brakes?

I would say more of an antifreeze smell.. just slightly though. I've checked for leaks and cannot find any.It runs great and temp seems fine.

I had the leaky grease from a seal on the exhaust problem. Smell was transient and car worked fine but cause of smell became readily apparent when I put on ramps and crawled under. Was fixed under drive train warranty. Frank

Get your car undercoated at walmart and you'll smell some grease burning on the exhaust alright :)

What's burning coolant smell like? Hot rubber bands (elastics)?

I've noticed the aforementioned smell wafting from my US 2002 Legacy, and have noticed a gradual "using" of coolant, but haven't noticed any external leak.

Take a look at where the lower radiator hose connects to the thermostat housing - check that junction as well as the thermostat housing itself. I had a slight (occasional drip) from there - it only dripped when the car was running, and was immediately vaporized on the exhaust manifold. (you really need to get under the car, or use a mirror, to see that area well.

I had what smelled to me like burning rubber, but it was oil from numerous leaks on the engine of my '97 Legacy, hitting the exhaust manifold when driving at higher speed. A change to high mileage type 10W-30 oil, with additives seems to have slowed the leaks down.