'Vacation' Reboot Child Actors -- Trippin' Out and Gettin' Paid

"Vacation" actors Steele Stebbins and Catherine Missal will have plenty of spending money on their next road trip ... the child stars are making bank on the famous franchise reboot.

Clark would be proud ... the 11-year-old Stebbins is getting $65K to play Rusty Griswold's (Ed Helms) youngest son, Kevin ... if producers go for a sequel he'll land another $150K.

Missal -- who's just 15 -- is looking at a more modest $15,600 to play Adena -- no doubt a love interest for one of the two Griswold boys.

The best part ... they probably have no idea what Wally World is ... neither kid was even alive for the first four National Lampoon Vacation flicks.