Bike racks secure against thieves?

[antspants]

If I need to leave my bike on my car parked outside work for the day on a regular basis, are there any particular bike racks that are known to be more secure than others?

Ideally I'd go for a tow bar mounted rack that I can easily remove, fold up and store in the boot when not in use. But I wonder if "easy to remove" and "secure" are compatible requirements?

I'm assuming a roof mounted rack would be less easy to remove (??) so if I'm taking the bike every 2-3 days I'd never take the rack off the car.

Obviously once I get to work then I can lock the bike to the rack with a D lock, but is the rack locked to the car and difficult to remove?

Any recommendations?

[Watchman]

I would bet none would stop a thief prepared to damage the rack but the Thule 909 locks onto the towbar and has a lock for the outermost bike which allows you to twist the unlocking screw but it won't actually unscrew - i.e. it locks "open".

[Watchman]

I wouldn't leave mine out of sight for any length of time but I have left it at a motorway services while I ate. I was not comfortable doing so but sometimes you just have to live your life and not worry that someone is going to screw you over all the time.

[CoolC]

Is there no way you can store the bike inside while you're at work? I'd feel uneasy with my bike on show outside all day no matter what the security was like.

[antspants]

CoolC said:

Is there no way you can store the bike inside while you're at work?

Not sure yet.

Just trying to decide whether next car should be an estate or large hatch so the bike can go inside, or if something smaller would be ok with a rack.

Currently I have a people carrier which is ideal for chucking a wet and muddy bike in the back without any dismantling. However apart from bike transportation I just don't need that much space.