You asked about roads to Puerto Lobos. Unless there's been unusual weather, a Subaru should make it just fine. But I'd suggesting not trying to do Lobos if you're only down for a weekend. It's 2 hours each way. Closer to Rocky Point - like a half hour drive - is La Pinta estuary which someone mentioned earlier. You'll probably catch some kind of fish there if the tide is coming in. Take the road to Santo Tomas/Desemboque/Puerto Lobos and turn off at the old house ruin near Kilometer marker 32. Consider taking along a portable air compressor as you might need to reduce rear tire pressure to about 10 lbs. That goes for almost anywhere near any beach - not just La Pinta - and even for pulling off the highway. You likely won't need it if you're careful, but better to be prepared.