License Plate fastener size 2008 Sedona: Improvised solution
What I’ve done so far – I needed to get permanent tags on by March 22 – was to go back to the hardware store and try out some other sized fasteners. A 5mm diameter by 16mm long by .80 pitch bolt worked fine for the front bumper license holes. I’m not sure those holes actually have any metal threading in them as the fasteners can still be turned even when the bolts have fully snugged the front license plate against the front bumper cover plastic. But, the front plate seems to be on securely and I am satisfied that this will be my permanent solution for the front bumper license plate. I did get the bolts in stainless steel because of the use of rust producing de-icers used on the highways in the winter in my part of the country (rust-belt).
As for the rear liftgate license plate: The 5mm x 16mm x .80 pitch fasteners used on the front went nicely into the metal threaded bolt receivers on the rear liftgate and I initially thought they would be the solution there too, but then, when there were fully turned down, the bolts keep turning and released without holding. This hardware store didn’t carry any 6mm bolt with any other thread pitch than 1.00 to try. The auto parts section of the hardware store did carry a black nylon license plate bolt that was the same 6mm x 20mm x 1.00 pitch that I did try unsuccessfully in stainless steel over the previous weekend. The idea was that the nylon might be slightly more flexible than the stainless steel of the other 6mm bolts and engage enough threads of the license bolt receivers in the liftgate to temporally hold the rear plate on to the liftgate without doing too much damage to the threads in the liftgate bolt receivers. This would be until someone on this forum can come through with the actual license bolt specification for the car or until I could get the spec from somewhere else. Then, knowing the correct spec, I could use the proper size tap or thread chase to repair the bolt receivers and use the proper bolts. The nylon bolts work – they seem to screw in about 1/8’.— which seems to be enough engagement to hold the plate on temporarily barring gale force crosswinds. I undid the two nylon bolts after trying them and cut down the length of each 20mm nylon fastener to about 9/16", so that even though they only go into the bolt receiver holes about 1/8’’, the heads of the bolts would actually snug up against the license plate and it’s plastic frame.
So far after 2 days of driving – at speeds as high as 55 mph on two days of moderately high springtime (March) winds (gusts to 25 mph) the rear plate has stayed on.