I recently put together a Thule 4 crossmember system (8 towers). I used the 387 7 in towers with 78 in load bars. The towers were $110 ll bean for 4 towers, 38 for 2 78 in bars (need 4). There is some flex to the bars, in the center, so I am going to try to place under the top bar, a 65 in load bar standing tall wise and connecting them together using u bolts--(for the full spare wheel).

Another option is to use Quick and Easy brackets which use a pipe or 2x4 for the crossmember. 818-358 0562 (they are not answering their phone).