Securing roof rack gear

Not a whole lot you can do but we use coil type bicycle locks. No idea if this put anyone off but haven't lost anything so far.

Stuffing everything in a Rack Sack also helps a bit as thieves cannot see the contents for an opportunistic 'grab & run'

Wow bad luck...I secured my spare wheel with bike cable and padlock.I know if people desperate they could cut cable if have cutters ..

I just have crappy gear that no one would want.

I didnt have a roof rack due to being overweight. Tinted all the windows so prying eyes couldnt see what was worth pinching. Worked for me.

I got a dozen bike combination locks from the dollar shop. If any thief looks closely enough they'll see the combination tags still on them - but I don't rate most of them as that intelligent and I haven't been proven wrong yet.

I have a "Lock Alarm" cost $48.30 from [I cannot remember].
Look up www.lockalarm.com it is a 15' [4.6m] ultra hard steel cable [plastic coated] you wind it around and through whatever and key locks on, 9v battery required.
If tampered with or tried to be cut it screams [120 decibel siren] that can be heard from a long distance away.

PeterH