Yup there's an array of hints given via future visison, but heres a few extras:
1)Through the secret tunnel inspect the Junk to find Carol and complete COPS
2)Stinky would have a place she meets S on speed dial? Perhaps her phone and the note can get a new location (via Crime-Tron)
3)You find a clue on the roof of Meesta Pizza. If only there was a pigeon flying between the ground level eating stuff and the roof and if only it could eat something that you could use to reach the roof
4)Grandpa Stinky has the shot glass. If you haven't already check out the Mole Processing room on Skunkape's ship. Interestingly Stinky's phone gets put in the personal belongings bin letting you teleport to that room.
5)If you keep telling Grandpa how you love Skunkape, he has to hold angry Max back
6)With Stinkys phone in the belongings bin teleport to Stinky's Dinner. Get Grandpa to touch Max then exit the convo and teleport to Stinky's cell. Grandpa's belongings are left with yours in the belongings bin where you can grab em