Got these finally but the lug nuts protrude out a couple mm in the hole. This would prevent the wheels from sitting flush against the adapter wouldn't it?

 

That is not right, the nuts should sit just below the surface, looks like they sent you the wrong nuts.

 

No, that is right. There are massive depressions on the back side of the wheels that allow the nuts to nestle into them:

 

Ditto, just make sure the lugs have full thread engagement and clear the wheel openings.

 

Looks like it depends on the brand/manufacturer of the spacers, I've bought 3 or 4 sets over the years and on every single one of them the nuts fitted just below the surface and I never had to worry about the size or shape of the hollows in the backs of the wheels.

 

With factory rims as above you won't have a clearance problem.

Your main concern will be the factory studs being too long, long enough to make it out to those indented areas of the wheel. Where the X is at and the raised areas at 12 and 2 o'clock.

Even if you don't grind or don't believe you need to grind down the factory bolts, after driving a short while listen in a quiet parking garage for a whooshing noise while driving slowly. If you hear it, that is the bolt rubbing on the inside of the wheel.

Also, the car will drive unbalanced. Contact via one or two studs and not the others will make the wheel rotate off centered.

Happened to me on 17mm studs and Gyrodynes. Easily fixed with a Dewalt grinder and under 3-4 mins per corner. Grind them all flat and stop. You will see they are domed with some having an M stamp on the end of the bolt. Then you have a 'measureable' point and you don't under or overgrind certain studs. You remove about 2.2mm.

As others have said here, the hassle is worth it. Car looks so much nicer with spacers. Best mod I've seen.

 

hoping i don't have to do this as thats the reason i bought 17mm spacers as others have suggested on the forum.

 

Yep I was hoping in one hand ....

If you have 20" Gyrodynes and 17mm spacers they just BARELY touch and will mar the inside of the wheel just slightly.

Any contact though needs to be dealt with - a safety issue. I am sure many who believe they are not touching on the forum will find out that yes, they are when removing their wheels for service.

Any wheel shop can grind them down to flush for <$50 I am sure. I would just do it.
There is nothing negative about the grinding since the OEM stud threads don't even start until way past the grinding point.

 

I seem to remember another 17mm / tornadoes owner reported he did not have to grind - so I was hopeful, but mine required a tiny bit of grinding. No regrets though! ymmv