430 RIVNUT?

So I’m swapping out my stock diffuser for a carbon fiber one and when I started removing the four 10mm bolts from the front of it, two of them just spun and wouldn’t come out. I was able to cut the bolt heads off and punch out the old rivnuts with the shank of the bolt still left inside it. The two that just spun were in the airfoil shaped rear lower crossmember.

I’ve ordered a rivnut tool and an assortment of rivnuts.

My question for everyone is, are there going to be any surprises after the parts come and I start back at it? I have experience using rivnuts and the tool from when I worked as an A&P at the airport.

What was supposed to be a 1/2 hour easy project turned into a lot of swearing, and a burnt finger from picking up a hot large area washer (dumb, just dumb).

 

Sorry, I’m not selling it.

 

It’s my car, and it’s been babied. The gearbox oil was changed a year ago and a new screen and o-rings were installed the year before that.

Rivnuts work themselves loose sometimes.