Since you have the most recent post here, have you made any progress? I have the same exact problem.

 

A big thumbs down to Hyundai on this part of the frame design!

In my case yes the nut had broken away from the frame, as well as the bolt was completely rusted to the bushing.


You will need a sawzall or torches, a angle grinder, a rotary tool(dremel) w/ reinforced cutting discs, and a welder.

First off take your sawzall or torches, and cut the arm off as close to the bushing as safely possible. remove the rest of the control arm you might have to cut the nut off by the wheel bearing aswell I did. Now using the dremel, cut a inch by in hole in the SIDE of the frame right where u can see a piece of metal folded over and welded on that is where the nut is. Your going to have to cut a hole big enough to get a mig welder in there and weld the nut back onto the frame.

Note let the dremel work it will burn through discs like no tommorow if u push hard.

if this does not get the bolt out you will have to then using the dremel cut where the control arm goes around the bolt on both sides, and remove it. Then use an angle grinder and carefully rotate the bolt around and cut it without cutting the frame. and buy another bolt and washer (GET A RATED ONE DONT BE CRAZY!)

It took me 3 days to get it out and put the new one on its not a job for the faint hearted and is extremely frustrating.

Dont forget to weld a plate back over the hole in the frame when your done!

And just so u know I offer no warranty for this, BEST OF LUCK!

 

Having same exact problem on my 2001 accent drivers side. Did you get the bolt out or did you have to cut into the subframe and weld the nut back?