If you choose to drive in Mexico, there is something a bit different in driving customs there than in some sections of the US with regard to the Left Turn Signal. They use it first of all to indicate a pending left-hand (usually in conjunction with a slowing of the vehicle and a flashing of the brake lights). A second, and possibly more common use, is in a “Caravan” of vehicles to indicate that the "leading vehicle" considers it safe for the "following vehicle" to pass. This is extremely dangerous in the situation where the leading vehicle really intends to turn left, and the following vehicle interprets that it is OK to pass. I’ve seen this used in the US mostly by long haul truckers so it wasn’t totally foreign to me.
You need to make sure that the leading vehicle is actually telling you that it’s OK to pass and not actually making a left turn. A lot of time they will put there hand out the window and wave you past them, otherwise check for possible left turn points and pass only if there are no places this vehicle could possibly turn into. When a Mexican driver is going to turn left, there will often be some arm-waving and a movement of the vehicle into the other lane (if that lane is empty) - this allows you to pass by in your regular lane.
If you intend turning left and there are following vehicles, then slow down and have your brake lights on when you activate the turn indicator. For good measure, open the window and use a hand signal as well.
One last use of the indicator is to warn other large trucks or RVs when they are about to pass a large vehicle going in the opposite direction. As most drivers know, there is suction from these vehicles which effect larger vehicles and RVs even more (yes large trucks SUCK!!! :) )
I guess I’m a bit of a coward. I’ve only brought a car into Mexico once and that was just to order some iron gates and the car always remained in site. I’ve heard too many horror stories about US citizens driving deeper into Mexico. A better option for me is taking one of the bus lines from San Diego.
If you are a braver sort than I, there are no special permits or procedures if your travel is within the Border Zone (usually up to 20 kilometers south of the U.S.-Mexico Border) or the Free Trade Zone (including the Baja California Peninsula and the Sonora Free Trade Zone) .
One thing to keep in mind is that U.S. & Canadian auto insurance is not valid in Mexico. While Mexican auto insurance is not mandatory, it is highly recommended. If you are in an accident or other vehicle-related problems and you do not have insurance, you may be arrested and your vehicle impounded until the authorities can figure out the situation. The insurance can be easily picked up over the internet or by one of the many insurance companies that line the road to the Mexico entry point.
If you do choose to drive you will find the drive to Ensenada from San Diego takes about 90 minutes, and is extremely scenic and pleasant. The Transpeninsular toll highway running from Tijuana directly into Ensenada is extremely well maintained and safe. Many parts of the highway wind through the coastal hills hundreds of feet above the Pacific Ocean making for breathtaking views. There are three toll gates on the way, but normally there is not much of a delay.
Once you arrive in Ensenada, I would keep my car in one of the secured parking lots in either your hotel or some other private agency at night.
Forget the car. Take the bus from Tijuana to Ensenada and leave yourself free to enjoy the scenery. And once you leave Tijuana, trust me, there is some beautiul scenery. I daresay the Pacific Coast is even more beautiful in Baja than it is up north in the Big Sur.
Park the car in San Diego - you can do this for only $5 and walk to the station. The trip cost about $14-16 round trip and is and hour and a half each way. Just make sure you know when the last bus leaves for the return trip unless you want to spend a night in Ensenada!
Busses: I’ve done this solo a few times...it’s easy. I did the planes, trains, and automobile method. I flew into SD and then took a taxi to the Greyhound Bus Station (about $10) in downtown SD. From there I took the buss (one leaves about every hour) to TJ Central Buss terminal (NOT downtown), then another buss (ABC buss Co.) to Ensenada (again, one every hour). You can take different busses to other places like Rosorito and many other Mexican cities from TJ Central. The day was long, but relatively cheap way to go. Greyhound was about $8.00, and the TJ to Ensenada was about $11.00 -both roundtrip. There are several buss companies that leave out of TJ Central (not downtown station) and head to various locations.
This is also a faster method to get back in the states at the border. By car, you will sit waiting in line for hours sometimes.
Car: Easy drive to Ensenada or Rosorito from San Diego. La Linnea (or Border in English) can be a hassle, only because it is the busiest border in the States. Since the inception of NAFTA (North American Free Trade Agreement) many people commute to and from San Diego and TJ. (I would hate to do this everyday) But once you are across, it is a clear shot. Make sure you have a map and if you are renting, make you sure purchase Mexican Insurance! You can do this close to the border, or even when you rent the car from certain companies.
The highway that leaves TJ to Ensenada is a toll road. You will have to pay a $2.50 toll a few times before you arrive in Ensenada. If I remember correctly, there are 3 tolls.
The only way I know of getting there is by car. There's probably a bus that runs between Ensenada and Tijuana, and I know the city has a tiny airport, but since you'll probably need a car once you get there I would suggest you drive. Of course, this is tricky if you're flying to the West Coast as almost no rental companies will allow you to take a vehicle into Mexico!
Ensenada is very spread out and doesn't have a very extensive bus system. If at all possible, try to bring your own vehicle. Of course, this gets tricky unless you're driving to Ensenada from your home. If you're flying to that part of the world, this could be difficult, and unfortunately I don't know much about what options you'd have. Contact your travel agent for more info.
When driving by car it is best that you take one that is both reliable and not terribly flashy. The big thing to do is just before you enter Mexico there in Chula Vista you need to buy insurance for your car. Your standard insurance does not cover you to be in Mexico. Although if you talk to your carrier they may be able to sell you a temporary insurance plan for Mexico. I went for four days and it was $30 US.
When driving in Mexico be aware of the other cars, they don't value lanes as much as we do or the exterior of cars. A slight nudge or bump that might cause a scratch or warp is common place and generally accepted so try to steer clear. This doesn't mean it will happen to you, it's just a good idea to keep a lookout. When driving through San Diego to the border you of course go through Tijuana, you then take the 1D to Ensenada which is a real nice drive all the way to Ensenada. It's a real nice road and there are no holes the size of small cars on it or anything. This is because it is a toll road so bring some cash. When driving in cities at stop lights, you must immediately accelerate with the pedal to the metal when the light turns green or the locals will get pissed. Be quick, but don't be a dick. Most hotels take in cars to a private parking area, I suggest you do that as soon as you get to your destination to avoid any stress. Gasoline pumps generally only accept cash in Mexico. So, be prepared.