Most of my earlier customs are a total fail to me now, but at the time I was super happy. My Zarana is perhaps the one that's aged the worst, yeesh.
My first Airtight WIP was godawful. Oh man, I didn't even post pics. It now survives in the parts bin, but will likely end up in the trash one day, it's so far beyond repair and not worth stripping the clumpy yellow paint.
I also had a huge accident with thinner once. I made a custom Alternator Ratchet, Ironhide and Trailbreaker (and lost them in a fire after all the stress over this whole accident anyways, so the "accident" with thinner ended up being short-lived) and was super tedious with the pin removal, being careful not to melt anything... And then I ended up accidentally getting thinner on the windshield of the white Jeep.
Why was it such a fiasco? Well, it completely melted the windshield, and it was a KO Alternator that ran me about $60 from China, that was almost impossible to find 4 years ago when I made it... I think they're all but impossible to find now. I had to rebuild the windshield from scratch, but it ended up looking awful if you inspected it closely.
Fortunately, I have replaced it and I have the parts sitting in a box to remake all 3. I'm just waiting on the Ironhide head to be re-cast by the original sculptor. (Also, I now know to keep thinner far away from the windshield.)
Luckily, in bot mode (which it stayed in most of the time) I kept the top on, upside-down on the windshield to hide it. Sort of a backpack.