Just a FYI  this was on a motorhome forum I use.  It really works so hope it helps someone here.  We have mostly used it on very nasty, rusted exhaust manifold bolts on Cummins Diesels, turboed high temp fasteners,  Since it gets those off It should get anything on a Suzi.

From April 2007 "Machinist's Workshop" magazine comparison test. They arranged a subjective test of all the popular penetrants with the control being the torque required to remove the nut from a "scientifically rusted" environment.
Penetrating oil ......... Average load
None ..................... 516 pounds,
WD-40 .................... 238 pounds,
PB Blaster ............... 214 pounds,
Liquid Wrench ............ 127 pounds ,
Kano Kroil ............... 106 pounds ,
ATF-Acetone mix............ 53 pounds

The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic transmission fluid and acetone. Note the "home brew" was better than any commercial product.

Of course soaking well over a couple of days increases the odds that you won't strip or break something off.    

As JOG said:

That, "acetone and transmission fluid", 'trick'.
Was told to me, by my Grampa,
when I was just a young lad !!!!!!!

It's works the best, and is the cheapest!