I put ebay flares on a couple of years ago and had the same problem with the rears. I'm a bit surprised they still sell them like this
Anyway, as someone mentioned, I just cut out some of the tabs and got the rears to fit well enough. Obviously this shouldn't be necessary but I'm happy with the overall result.
I was quoted $1500 for OEM flares and paint by the dealer, so it was worth the risk. Best solution however would have been to option 20"s from the outset and get the flares included, but I didn't realise this at the time
