Thanks guys!
I took a look at my rack and there are no cutouts for cables, but it’s not a super-hard material, so I may try taking the dremel to it to cut out some reliefs.
I probably won’t go for the roof rack yet, because I’m leasing a Saab and my next car will probably be another make (long story). Saw an interesting hitch rack today, made by Saris, that holds 3 bikes using fender-like cradles. I believe it’s the Thelma model. Not that I have a hitch to work with, but…
I may also look at getting some blocks of stiff silicone and carving them out to make a pair of "adapters" of sorts, to fit over the cables before dropping the bike onto the rack.
Thanks again for the replies!
Cheers,
Dave