Yes, you are right, when you allow the oil to drain for about 15 mins. and if what's kept inside is fully synthetic it will keep up with what it's supposed to do I guess. I tried a couple of weeks ago to loosen the two 10 mm bolts in the backpart of the guard (drilled in the subframe I think), but couldn't release them, have given them a good shot of WD40 so I hope by now the product has done it's job. Besides just bought a new 10 mm spanner today. (I tried it with an open spanner, which resulted the bolts started to get round so I stopped the attempts, now bought a ring spanner in the hope this will be better).