Update on the new heat exchanger replacement. Total cost $125.00! It was a 5 hr job (4 hrs and materials included in the warranty) but I helped alot. The tech was pretty fast and if I hadn't been there to help it could have easily taken 6-8 hrs. (I got permission from the tech to do this) Also you should expect to pay for a dignostics charge of around $100 prior to the install to tell you what you probably already know. This typically happens before the dealer will order the parts under warranty. I didn't have to pay this since they saw the pictures of the rusted out exchangers.
I am very happy with this repair. All in all- If you could get this done for $350-$550 I believe it is well worth it. It may still be a 20 yr old furnace but the blower fan is now clean, there are new primary and new secondary heat exchangers installed and all other major components have been checked. The house is heating like it did when the furnace was new and as you can see by the pictures, the guts of the furnace are brand new.
Remember the verbiage of the lawsuit in my earlier post-- ..."under no circumstances, however, will a Class member be charged for labor required above and beyond 4 hours of labor...." Technically I shouldn't have to pay a dime for this but I think it will be hard to find a tech willing to do it for nothing. (remember it has to be an authorized dealer before carrier will reimburse them) The tech charged me their hourly rate for that hour. I had done quite a bit of work prior to the tech arrival (removed all the stuff in front of the exchangers)-
I had a great tech. One of the few women techs in the industry I image. Heather from Allpoints heating in Mukilteo, Wa. If you are from this area call and ask for her. She washed the inside of my furnace and left the place spotless! I don't think a man could have done it any faster---

Installed primary and secondary

The secondaries had rusted all the way through as you can see in this picture.