Well as long as your vehicles are running full blown Windows, I don't see a problem with them being in a police car but that's a pretty cool setup I must say. =P Your pseudo code (IMO) should look like this:

Code:

$prog1 = 'exe1'
$prog2 = 'exe2'

SHELL "%path_to_exe1%\"+$prog1

While @ERROR <> 0
  EnumProc($prog1)
  Sleep 1
Loop

;; Now you may want to set a sleep offset depending on
;; whether the condition exists where the program, even
;; though it may be started, needs to wait a few secs 
;; before kicking off the other...

SHELL "%path_to_exe2%\"+$prog2

Function EnumProc($exe)
  Dim $winmgmts, $ExecQuery, $Proc, $ID, $GetObject
  $winmgmts = "winmgmts:{impersonationLevel=impersonate}!//" + @wksta
      $ExecQuery = "select * from Win32_Process where Name='" + "$exe'"
      $GetObject = GetObject($winmgmts).ExecQuery($ExecQuery)
      For Each $Proc in $GetObject
        $ID = $Proc.ProcessID
        $EnumProc = $ID + "|" + $EnumProc
        Next
      $EnumProc = Left($EnumProc,Len($EnumProc)-1)
      $GetObject = ''
EndFunction



of course you'll probably want to add some more error checking in there but that's at least how i'd structure the nuts and bolts. gurus, please make sure i'm not telling this man's car-computers directions to McDonalds. =P