Check with the folks at Special Edition for stuff like this. @chines1 (Carey Hines) has always been responsive. By the way, I'm pretty sure that the body is bonded to the frame with adhesive. There may be some bolts in some areas, but there is no danger of the body coming off.
That doesn't sound like something that would need an accurate torque setting. I'd just apply red Locktite and crank them up tight. Maybe the flexible adhesive used to bond the fiberglass to the chassis dried out.
For a 17mm nut, the proper torque for that depends on the bolt grade. Ace Hardware grade should see 38 ft. lbs. and Grade 8 is 50 ft. lbs.
Here's a Handy Chart for yah. Just click on the blue highlight.
I would also put some locktite blue on them, or a flat washer and lockwasher against the nut, or toss those plain nuts and get some 17mm nylon insert stopnuts (sometimes called "Nylok nuts) instead. Those shouldn't loosen up.
The chart Gordon links to above is handy, but only refers to maximum torque values. While these values do apply to high torque applications like lug nuts and axle nuts, they would not apply to low torque uses, such as an oil pan drain plug. Gordon's suggestion of lock washer and loctite is a practical solution for many automotive uses. Overtightening can cause damage to the fasteners themselves and to the parts being joined.
No official torque spec for the body to chassis bolts, but I'd suggest the same torque as a 10mm VW body to pan bolt which is 15-20 ft/lbs. They are nylock nuts but they do have a rubber pad between the frame and body, which may have shrunk or flattened out over the last 16 years.
As mentioned above, the body/chassis is bonded from stem to stern and the bolts are mainly used for alignment purposes when the chassis is inserted into the mold. You'd be fine without them, but there is also no point of having loose bolts so just snug them up.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .