Stone chips on car from bike rack

[Tony4wd]

After transporting bikes for a couple of years I've just noticed a bunch of stone chips in my tailgate paintwork. I think stones thrown up by the car tyres have been bouncing off the bike tyres and hitting the back of the car - not thrilled to find a couple dozen stone chips where there shouldn't be any.
I've fitted larger generic mud flaps to the car so now the bikes and rack are completely protected. A fair bit of mud used to get thrown onto the bike wheels before too so that problem is also gone.
These are the mudflaps I bought - seem like they should last a while: https://www.ebay.com.au/itm/2042699...rsboxnuja42fmdf9GTG0fGaluw==|tkp:BFBM0Nbm_LNi

 

[Plummet]

Picture of the rack with bikes on it?

 

[Tony4wd]

Here's the rack with the old car mudguards. I figure if there's a direct line from the car tyres to the bike tyres then stones could hit the back of any vehicle - might save someone a few chips before they realise what's going on.