>>>I would also recommend replacing the bolts discussed above (the ones that hold the camber shims) with stronger bolts. At least on Exiges these bolts are only rated about 8.5 if I remember right and several people have sheared these when running slicks. I have replaced mine with 12.9 strength bolts.<<<
I just inspected some bolts that had failed on the rear of an Exige. They exhibited signs of metal fatigue on one portion of the cross section. And the rest of the bolt showed the sudden snap which occurs when the remaining cross section is no longer sufficent for the experienced loads.
The failed bolts were 8.8s. The US cars use grade 10.9 bolts which are about 25-40% stronger than 8.8s depending on how you look at it. Note that when you change from 8.8 to 10.9 or 12.9 the tightening torque needs to change too. Otherwise you'll wind up with a weaker setup! There is a bit of a balancing act going on here...8.8s are less strong but they tend to bend instead of suddenly snap. More is not always more.
Also, the loads in the back of the car are likely higher since there is so much more weight back there, and the spacing of the two bolts on the upright is much less than at the front of the car. Narrow spacing increases the importance of the installed tension achieved by the fasteners. Remember that a properly torqued bolt has a large tension on it and is actually slightly longer than when uninstalled. They are stretched like springs. If the loads the assembly sees are less than the tension can handle, the assembly will be stable and long lived.
If you're changing bolts I'd do whatever Lotus suggests, which may very well be to use 10.9s torqued to a higher amount than 8.8s. Don't overtorque bolts either. The torque is calculated to achieve the desired installed tension the design requires and can handle. If the uprights and related parts are the same on your Exige and the 111R, then this should be okay to do even without contacting Lotus, since 111Rs use 10.9s. Use the proper torque and thread locker. The bolts are also cheap and readily available from many sources so it may be a good idea to replace them on a schedule or whenever the bits are reassembled. We are talking about pocket change dollar amounts here for some peace of mind and safety.