Oh wow... Are you sure about it being the exact same car for her trip to Coachella? I mean, the Overhaulin' production company would definitely be able to give the dates of filming - but in any case, I highly doubt that it was 3 years before airing.
Something else that stuck in my mind is she said he agreed to do the show (it wasn't actually a surprise according to her) because they would pay for the work on the car, so Johnny wouldn't have to foot the bill: "Actually, it was only agreed to be on that show when I found out that it would save him the money in having to actually pay for the restoration." (page 16 from yesterday's transcript).
Right, because Johnny is known for volunteering to be on tv shows and being a cheapskate. I'm at a loss for words, and this is such a minor, unimportant detail compared to everything else.