Yup, I'm traveling alone. I guess it could be dangerous, but, well, nothing's happened to me so far. Not even a situation where I felt like I was in danger.
The thing is, I'm a tall guy (2mts), and not dread-thin either, so I'd like to think I don't look like a pushover (I am, really, just a big softie without much fighting experience whatsoever, hee). Also, I think it's a lot easier to get a ride with one guy than with two guys.
I mostly stay in hostels, yes, but in Argentina I needed to sleep outside once. That time I slept in a field near the service station, after asking the station owner whether I could. I'd always do that, and try to get his name, so you can invoke it if some random guy or a cap comes along to get you out of there.
In the Lake District & Chiloe, I remember seeing loads and loads of service stations. Nearly every town seems to have one. And since towns are usually not much more than 50kms apart, that's good enough. I *think* there were fewer on the Carretera Austral, but I wasn't really paying attention then. Too busy looking at the marvellous scenery. Anyway, try taking a look at
http://www.copec.cl - it seems to have a list under 'estaciones de servicio'.
Myself, I'm taking the train up from Temuco, just because I like the rhythm of trains so much. I might go hitching again in central Chile or back into Argentina.