Rust repair recommendations for 2007 Prius rocker panel?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by bnprius, Jan 9, 2026 at 3:02 PM.

  1. bnprius

    bnprius Our Prius at 200K

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    My 2007 Prius joined the Priuschat 200K club sometime ago and is now at 220,000 miles. We have had it maintained since it was new by our local Toyota dealer, and mechanically it is in excellent condition. But it has a rust problem in the rocker panel just ahead of the passenger-side wheel well. There's an inch-sized hole, and there's rust for a few inches ahead of the hole. We would like to keep our Prius to at least 300,000 miles, but salt here in Michigan poses a huge problem. We have had a Canadian-based rustproofing treatment, called Corrosion Free, done to the car every other year. What suggestions would you have for repairing this rust damage and stopping future rust? Oddly, the driver's side shows no rust. Will attach a few photos.
     

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    #1 bnprius, Jan 9, 2026 at 3:02 PM
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    The only real fix is to cut it all out and weld in new metal and then re-paint. With that degree of corrosion visible there will be plenty more in less visible areas.

    Repairs can be done but it's likely to cost more than the car's current value.

    Lots of cars (including Toyotas) are built to last ~15 years in salty winters. The fact that you've already gotten nearly 19 suggests you've done a great job with maintenance and anticorrosion treatments.

    I suggest enjoying the car while you can. If you really want to get 300k out of it, drive more than usual.
     
    #2 Leadfoot J. McCoalroller, Jan 9, 2026 at 4:09 PM
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  3. BiomedO1

    BiomedO1 Senior Member

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    That wouldn't really concern me; but I'd get a structural inspection of the under carriage and any vital weight bearing member. That's what's really important.
    This is a common problem, which calls for a common solution. They make diamond plate glue-on panels for 4x4's and some cars. That would be the cheapest and quickest option.:po_O to get you to 300K.
     
    #3 BiomedO1, Jan 9, 2026 at 4:52 PM
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  4. bnprius

    bnprius Our Prius at 200K

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    Thanks for your replies, Leadfoot and Biomed01. Yes, none of the structural parts of my Prius are rusted, according to my Toyota dealer, and that's all-important in terms of deciding whether to do this kind of rust repair.

    Yes, I realize this repair would cost more than the value of the car, but I've already paid that much for replacement parts that are critical to the safe operation of the Prius, such as new struts (OEM) all around. See my post at 200K, 200,000 Mile Club | Page 40 | PriusChat

    I did find a previous PriusChat post that addresses this exact (and very common) problem in the 2nd gen Prius, and the first reply specifies a Toyota OEM replacement part that might work for a good body shop--see:
    Source for rocker panel rust repair pieces ? | PriusChat

    If anyone has done this repair on a 2nd gen Prius, please let me hear from you. Thanks from this longtime PriusChat member.

    Bill Nolting, Ypsilanti Michigan
     
    #4 bnprius, Jan 10, 2026 at 2:36 PM
  5. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Agree. That rocker panel is likely the tip of the rust 'berg. How long ago was the underbody treated with a rust guard? I'd want to have a good look at the underside and wheel wells, including removal of any plastic shields.
     
    #5 Mendel Leisk, Jan 10, 2026 at 2:46 PM
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  6. bnprius

    bnprius Our Prius at 200K

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    Thanks, Mendel, my Prius has been treated by a Canadian rustproofing company called Corrosion Free, every 2 years. They spray all the internal and external panels. It has worked well except for this one spot.

    As I mentioned, my Toyota dealer carefully inspected the frame/underbody of my Prius around 200K, and said there was no rust damage to structural or functional parts. I will ask them to repeat this inspection before doing this repair, though.

    Bill
     
    #6 bnprius, Jan 10, 2026 at 3:56 PM
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