*Indy and Marion are about to kiss at the end of Raiders of the Lost Ark, when three sonic booms are heard. They look up to see the DeLorean on the drive way. It's knocked over a few trash cans. Donovan gets out, wearing late 50s clothing.*
Don: "Indy, you gotta come with me!"
Indy: "Where?"
Don: "Back to the future."
*Donovan goes through the trash can, picking out some rubbish, finding a copy of Indy IV and a gopher, stuffing them both in Mr.Fusion*
Indy: "Wait a minute, what are you doing, Don?"
Don: "I need fuel. Go ahead, quick, get in the car."
Indy: "No, no, no, Don, I just got here, OK? Marions here, we're gonna take the new truck for a spin...!"
Donovan: "Well, bring her along. This concerns her too."
Indy: "Wait a minute, Don. What are you talking about? What happens to us in the future? What do we become one dimensional assholes or something?"
Don: "Yes. Im afraid you do..thanks to a man called Speilberg.
But It's your kid, Indy, something has got to be done about your kid."
😛
Indy V could then be them unravelling the damage that was the hideous alternate universe that was Indy IV with the aims of righting all wrongs with the aim of saving his Dad and Marcus. (The latter of course portrayed by a Denholm Elliot impressionist and CGI)
This would redeem the series, be a nod to another Spielberg involved great of the past, AND be a way to redeem the use to CGI in Indy films, kharmically.