Looking for rear window repair advice

Hi - back window got smashed in, and looked to have it replaced. Friend said he knew a retired cop who used to do them for local police department, and does them as a side gig now. He said it would be OEM (it wasn't when he opened the box, to his surprise). Had him put it on anyway (probably a bad call). So he put it on, and it leaked/was loud. Brought it back to him twice without much luck on fix. He said he finally knew what the problem was (that is was the primer he was using). Then unfortunately, the old timer passed before I could bring it back.
So the situation worsened with the latest freeze/thaw and it leaks a decent bit along the top seal and is pretty loud.

What are my options? I'm new to self-fixing, but and eager to learn and hear advice. Is this something I could potentially rectify myself since its only that top seal that is leaking (reat of the window works great), or am I gonna have to throw a bunch of money at someone else to fix it?

 

Option 1, have someone who knows what they're doing do it.

Option 2, caulk it and don't worry about it.

 

Is there a caulk you recommend? Again, working from slightly-above-ground-level so far as knowledge goes. But looking to learn, and I find that specifics help.

 

You can search it on Bing and there are several, here's one solution.