Tow bar help!

Brought a nice LR 3.5t adjustable towbar for the discovery, but I can't fit it as the gas tanks and relocated petrol tank obstruct the bolt holes. On the near-side I may be able to cut the bolt down to fit or use a few extra washers but on the petrol tank side even dropping the tank doesn't help as there is insufficient space for the bolts.

Any miraculous thoughts on what I can do short of removing all the tanks and ........

Or will I have to fit one of those cheapy towbars that only fix to cross member.