Looking at rear muffler repl...

Is the beg really that bad? Generally (on other cars) those begs mounted on body are still good for multiple muffler replacements. I think you could just fit a bolt or alltread in place of that beg by drilling through "frame rail". It doesn't even need to be exactly at the same point. You could just bend it to get it aligned. All you would need is bolt or alltread, nuts, and washers. Also you could use many types of universal exhaust mounting bracket or just bend a mounting bracket out of that allthread then you could bolt those through floorpan and still use factory rubber mount.

How is the underside looking otherwise? How bad is the rust? Where is it worst? These are just my interest so they have nothing to do with your question.

 

Welcome back!

Maybe one of the 'anchor bolt' options below, thinking 90/45 degree. Maybe it could be bent up a bit in the vice.

If there is no vice access, you might try a J-bolt, Hook bolt (square), U-bolt (square) after cutting off one end to make an easy hanger. Doesn't the dollartree have some cheapo coated hangers (bike hooks), it wouldn't be fancy or heavy gauge, but something to experiment with.

Bet the exhaust shop could properly sort you out for very little, as they must be replacing rotted hangers on the regular.

Check into some of the expanded metal, there are affordable galvanized and aluminum options.

 

Thank you to Hobbit for the excellent report with photos. We have a 2007 Prius, bought new, with 170,000 miles on it, and we live in similarly salty Michigan. I have had our Prius treated with "Corrosion Free" rustproofing from Canada, luckily available in Ann Arbor, in hopes of staving off overall rot, since 140,000. My aim is to make it to 300,000. I've always used Mobil 1 synthetic 5w30 Extended Performance, changing it every 5,000 miles, and the Prius still consumes no oil between changes. We had the radiator replaced at 155,000 miles when it leaked due to corrosion. Visible body rust is minimal, just a bit on the rocker panel ahead of the rear wheel.

On Nov. 6 our catalytic converter was sawn off our Prius in the middle of the night, despite it being parked next to my bedroom. I have State Farm insurance with comprehensive coverage and no deductible. They paid to have the Prius transported to our dealer, Victory Toyota in Canton MI, who confirmed the theft and sent photos to State Farm. After a long, long wait, State Farm agreed to pay the $3016 cost of a new OEM catalytic converter + labor to install it.

After looking at this and other posts about the rest of the exhaust system, namely the exhaust manifold and the rear muffler, I decided to pay to have those parts replaced, too, so that the entire exhaust system will be new--and hopefully good to go for another 170,000+ miles.

To combat the theft problem, I decided on the MillerCAT Stainless Steel Shield + Deadbolt, which costs $340, and which is carried by the Toyota Associated Products Program, totaap.com, so the dealer could order it directly.

Total cost estimate BEYOND what State Farm is paying is $1650, which includes the cost of the exhaust manifold, exhaust manifold heat shield, em gasket, rear muffler, and the MillerCAT Stainless Steel + Deadbolt, and labor (minus a $250 discount coupon offered by the dealer).

We should have our Prius back before Thanksgiving, and I'll post a report then on the results.

Bill in Ypsilanti MI