Hi.   I purchased a Brink 6065 detachable towbar for my 2018 skoda octavia Vrs.    Started fitting this morning, removed tailights, bumper etc, all no problem.   Towbar slides I to rear chassis legs like it was made for them. Looks great and then discover there are no holes in the chassis rails to insert the bolts. Read online about rubber inserts to protect thread's but none of those either.   Supplier swears its the correct bar and that I'm missing somet