A simple method of adjusting the tension on the side "flip-over" latches for the front & rear clips is illustrated in the attached pic. (This is for a DRB, but may be useful for other cars).
The mounting block for the latch is bolted through the clip via 2 slots to allow up & down adjustment. Below the block, I have mounted a piece of rt angle aly, firmly bolted to the clip so it bears on the mount block at the bottom of its travel in the slots. Upward adjustment of the mount block (increasing tension) is achieved by shimming between the mount block & the aly bracket. Once the correct tension is set, a dab of resin across the shims will lock it all together. Once the latch is flipped shut, none of this can be seen.
I hope that this will be helpful.