Here's new footage of Electrovolt.    
This shot of Electrovolt is when the Sentai footage starts up however the electrical bolts that are in the footage were added into the footage to make it look like Electrovolt "created" or "summoned" the new Bike for Elgar.
As soon as you see Adam, Kat, Justin and Tanya morphing, the following close-up shot of the Rangers' feet and the lower part of their legs is Sentai footage.
The shot of Electrovolt growing is Sentai footage.
All of the zord battle is Sentia footage.
All footage of Elgar being on actual land (which includes his Bike riding) is Sentai footage.
NOTE: Carlos and Ashley debut in this episode however I wasn't able to get good shots of 'em.
It's obvious Divatox recognized Carlos and Ashley from the Blue Senturion's Millenium Message because this is the only reason why she would have sent Piranhatrons after them.

Following info comes from Car 14.
Here's Electrovolt riding his Bike.
Here's Electrovolt.
Here's Giant Electrovolt. He grew using his own power after he absorbed both Bikes that he and Elgar were riding.
Here's Electrovolt and Robo Racer.
Electrovolt is destroyed by the Megazord Spinout Move and Robo Racer's Synergizer Blaster Mode.
Here's the Turbo Megazord and Robo Racer doing their "after-victory pose."