Front lower control arm - rear bolt seized
 

2016 Hyundai Elantra - rear bolt for front lower control arms (both sides) are seized in the bushing that is in the arm itselt. Bolt is seized to the metal sleeve of the bushing. I have removed the crossmember which holds the control arms. Does not appear to be room for a sawzall blade to fit in the space to cut bolt on both ends of bolt. Not sure what method to use to remove both arms. I did purchase a used crossmember and will install left and right front lower control arms. Thinking of a way to remove old arms from old crossmember, as the original crossmember is not rusted and could be used by someone else needing a crossmember. I purchased new parts (control arms, bolts, and lock nuts). I thought I might ask service department of local Hyundai dealer for any suggestions for removal of old arms, but was told at dealer that customers could not talk with service department persons (techs or manager) since they are apparently too busy. Any suggestions would be most appreciated. Thanks in advance.

Did you try some penetrating oil and an impact tool to work the bolt loose ?

Sounds like you need to torch it. Most shops will apply heat when bolts refuse to turn.