Phineas & Ferb meets Scooby-Doo! *I got really bored in lockdown*

This was just made for fun. I've been binge-watching Phineas & Ferb during this pandemic, thought their crossovers are good, so ended up thinking about a crossover with Scooby-Doo, as I really like that too, anyway got to the point where I thought I'd share it. I really wanted to add in:
-Vanessa Doofenshmirtz
-Buford
and Baljeet, but couldn't think of anything for them, so any ideas for anything extra or to fill in gaps are welcome, get creative!