I tried, but there's very little clearance in the grommet to squeeze the 1/4" tube. I was afraid about the long term effect of the friction against the existing wires/cables whenever opening and closing the trunk.You can use polyethylene tubing to run the cables, like what is used for aquariums RODI water systems etc. Dirt cheap and you probably only need about 6' of it. 1/4" Mur-lok Polyethylene RO Tubing