DinoShepherd

So you are going 12 hours race a Cervelo. This is cool. I need to assume that you have some level of disposable income.

Here's the deal: Any trunk rack will get your bike from A to B. Any rack that hangs a bike by the top tube (all trunk racks) will sway. Even if they have anti-sway cradles, they will sway. Over a 12 hour drive, you WILL get marks in the paint. This will piss you off.

Second (and feel free to contact them to confirm) major rack manufacturers are not thrilled about high-end carbon bikes hanging on these style racks. There are generally not recommendations against, but Yakima (for example) will steer you towards a rack that doesn't touch the frame.

The best example of this is the HoldUp. It is a hitch mount rack that only touches the tires. Really the premium solution for getting a bike from here to there.

-Z

Retro Grouch 

That's what I was thinking too. Out of the weather, away from the road grime, relatively secure from theft. You don't have to worry about if the whole rack is going to blow off of the car. The bike and/or rack isn't going to scratch the paint on your car. There's no wind noise and no impact on fuel economy. Any other concern you may have that caused you to ask the question - gone.

I think that the best bike rack is a canvas painter's drop cloth. You use it to protect the seats and interior of your car. Cheapest bike rack too.

deep_sky

Any determined thief will steal the bike, if it's attached to the roof, trunk, hitch, or even inside the car. What a lock and straps do for external transport is deter the casual thief. Have to work a little harder to steal a bike inside the car, but nothing is thief-proof.

I have a trunk mount (Saris Bones 3), and to prevent sway I have a strap I bind through the rear wheel around one of the vertical struts, and through the front wheel. No wheelspin, no sway, the bike is secure. There is an aero penalty (I can't get the car to go over 90mph with the bike attached), but rarely am I doing 90 for any length of time (kinda scary in a real light car like a corolla).

eddubal

Yeah, remember the truism: Locks are there to keep honest people honest. Over my twenty years shuttling my bike up and down the east coast, I found a bit of common sense and a decent lock will usually be fine. Park the car under a light at night. If you are going into a restaurant, park in front of a window if possible, and try to get a table overlooking your car. Even just being near the entrance will scare away most thieves. As others have posted earlier, do take the bike in with you if you have to stay at a hotel. It should be fine if you are in a populated, well lit area, but why take that chance, or give yourself something to lose sleep over. Do lock the bike since at the very least, it'll slow a thief down enough where it might not be worth it to steal the bike. You do have a nice bike, so it will attract attention and sometimes the bad kind. As long as you take some common sense precautions, you'll be fine at that end.

As for the bike rack, make sure that your bike is padded well where it's going to touch the rack. Pipe insulation works well. I've even seen people cut pool noodles to use to protect a frame. It's cheap and easy and good insurance. Pad it anywhere it touches the rack. The vibrations of the road can do some fair damage to the finish and possibly the frame depending on composition. Padding is good.

Generally you shouldn't have any trouble with the bike being behind the car. Splattered bugs come off fairly easily. You do get many less than if it's on a roof rack.

I have a roof rack, but it cost a lot of scratch, and every car is different and will cost more to put it on. If you're on a budget, stick with the trunk rack. It'll do you well.

Much luck and have a good trip!

Hangtownmatt

I agree with this. I use a trunk rack but rarely, if ever, let my bike out of my sight. If I were to leave my bike unattended I'd either get a hitch mount and lock it to that or a vehicle large enough to stow the bike. But you still need to keep in mind that with a locked hitch mount setup wheels, seats, accessories, etc. are still vulnerable.

My favorite advantage to a trunk mount is that when I'm out riding I can stash the rack inside the car. This way it doesn't look like I'm away on a bike ride making my car more vulnerable to thieves.

Matt