It depends which spacers you have as the H&R 'DR Trak+' ones come with their own bolts that fit the spacer to the hub and so you use your oem 27mm radius bolts to fit the wheel onto the spacer.
I notice that the link you gave isn't for 'radius seat' bolts which are standard on all Audi's.
I needed longer 35mm M14 x 1.5 radius bolts because I changed the wheels, but if you are keeping your oem's then with H&R whatever size spacer you get you won't need to buy any bolts as you can re-use yours.
However, I don't know about any other types of spacer, as I think these H&R 'hubcentric' spacers (only available for spacers over 15mm) are the best type to get- and mine have been excellent, also with lower Sports springs fitted too..

 

H&R COME WITH 2 TYPES OF SPACERS,the ones i have need longer wheel bolts,im not sure which bolts or size as ive stated above .

 

These were my observations a while ago on spacers and bolts. Might help.

https://r.tapatalk.com/shareLink?ur...om/forums/showthread.php?t=127025&share_tid=127025&share_fid=40299&share_type=t

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I'm sure everyone else will agree, but if you are running spacers 15mm and above to use HUBCENTRIC ones. That not only can you use the standard bolts (and locking wheel nut) but also are alot safer.

I've herd of horror stories of wheels coming off due to using longer bolts. The hubcentric spacers are a bit more pricey but not as expensive if your wheel falls off.

 

Hubcentric too :thumbsup:

Why would the wheel come off using longer bolts?

I have 15mm spacers on the back, none on the front. I test fitted the 15mm spacers on the front and felt the wheels stuck out too much. Looked like they would pepper the sills with stone chips.