Hate to see you put the cap thru your rear window. Can you have the slider installed AFTER the solid mounted hitch using the same mounting holes if needed? Try some slow tight turns with the non-slider and see if it makes you nervous. I have a friend that had a Chevy 6.5 ft box that had an older Reese 15k slider that never had to use it until that one time trying to cut his fiver sharp backing up his driveway and CRUNCH. It was all over but the shouting.
2010 Cedar Creek 5th Wheel 34SATS "The Beast"
2006 Ford F350 Lariat 6.0L Diesel
2003 Harley Heritage Softail "Hogzilla"
1988 Harley Softail Custom "The Fireman"
1986 Marriage to "Wifey" (patience of a saint)