Bolt sizes

[iMacThere4iAm]

Hello chaps,
I'm trying to put together a kit of spare nuts & bolts that are often handy when working on a rusty old 4. What sizes would you choose?

Alternatively I suppose I could get a set of too-long bolts and cut them to length when I need one.

 

[mojobaby]

I've just taken my exhaust off to clean and respray. I had to cut off two 8mm bolts and nuts that were used on the exhaust clamps, as they were badly rusted (being underneath the car)
I think the clamp where the exhaust goes through the engine compartment wall into the wheel area also has 8mm but that came off quite easily

 

[angel]

Apart from some M7 fasteners which are a little hard to find, R4 bolts and nuts consist mainly of M6, M8, M10 normal threads (very easy to find).