Assuming there's nothing wrong with the car, then the water drip is caused by condensation from your air conditioner.
behind the front bumper... look from the underside twoards the passenger side
At the bottom of the big black metal container near the front underside of the car, slightly to the passenger side of the car.
The horn has a relay. It is located in a black plastic box, in the front of the engine compartment (front Passenger side). Open the lid & you will see fuses & relays. There is a diagram on the underside of the cover.
Horn is located on passenger side front. Look from underside. It is about 4" in diameter. There is a plug with a clasp that connects from the top. release the clasp and pull the plug.
Second from the front, passenger side.Second from the front, passenger side.
There is a large plastic protective cover on the underside of the front of the engine which covers the bottom of the engine from side to side. On the passenger side close to the front of the vehicle there is a rectangular access port (about 6" x 8") built into this plastic cover. The access port has a cover which is removed using two screws that are right beside each other. The port cover slips out after these screws are removed and the oil filter is visible as soon as the panel cover is off. Good luck! It is quite possible that yours does not have the underside engine cover, many do not. If not, the filter is plainly visible from the underside of the engine on the passenger side closer to the front.
It is under the front passenger seat.It is under the front passenger seat.
the top one is located by the belts next to the valve cover. the bottom one is in the same location but right under the engine in front of the front passenger tire. you can see it poking out if you just look on the underside of the car.
It souds, by your discription, that the the front seal is failing on your engine. This typically doesn't cost much to replace the part itself, however, the time to do it is where a mechanic makes the money.
Look under the front passenger side floor pan near the transition to the firewall. Should be able to see condensation dripping if AC has been used.
Water dripping on the front of a portable air conditioner could mean that the air filter needs to be changed. Your evaporator coil may also be dirty.
The oil filter on a 2008 Saturn Astra is located in front of the engine. The oil filter can be found on the underside of the exhaust manifold towards the passenger side of the vehicle.