This one had a srimech (self-righting mechanism), a new body shape, and more effective forks, which were capable of completely overturning opposing machines.
The fourth model had improved skirts, and the srimech was updated to a top flipper, which was the favourite with the driver Kim Davies, who stated it was, in his opinion, the best version.
For Series 7, the fourth model was reused, with the addition of a rear skirt, and with the srimech being replaced by an anti-hammer cushioned top.
It also won the "Sumo Basho" competition in Series 4, meaning that it was the only machine to defeat Shunt in this event twice.
They returned next season with Scallywag, a wedge-shaped lifter with a colour scheme similar to Panic Attack.
The team captain of the robot was Kim Davies, who was originally joined by Kevin Pritchard and Lee Witcombe.
In Series 3, Pritchard left the team to create a similar robot named Evil Weevil and Davies was joined by his son Michael and Simon Rosen.
Christian Bridge won a competition in Robot Wars Magazine to join the team for Series 4.
Pritchard returned and took over the controls with teammates Paul Wier and then-webmaster of the official Panic Attack website, Jamie McGarry.
It managed to flip Whirling Dervish with its spikes in the semi-final, before winning the show by pushing Disruptor into the pit.
Panic Attack won its Eliminator for the Grand Final by immobilising Killertron, and subsequently pushed Sgt.
Panic Attack flipped over first Axios and then Toe Cutter to reach the Heat Final against X-Terminator.
In the semi-final, Panic Attack flipped over Thing 2 to advance to a battle for a place in the Grand Final, against Firestorm.
Spawn drove over Panic Attack, which lifted it and pushed it into the arena wall and Shunt[broken anchor]'s CPZ.
Although the American robot was heavier, Panic Attack easily turned it over with its lifting forks repeatedly but Rammstein was invertible and ran away.
After a while though, Rammstein started to lose power as its batteries were designed for three minutes battle rather than the UK's five, so Panic Attack picked it up once more and dropped it into the pit.
The force of a flip on Panic Attack from the latter caused internal damage, and after Wheely Big Cheese broke down, the judges decided on Firestorm 3.
Its self-righter was replaced with a hard rubber panel for protection against overhead weapons, and a large skirt was added at the back.
[3] In Round 1, Panic Attack fought Mega Morg, Edge Hog and Spin Doctor.
Panic Attack had its weapon immobilised by Tough As Nails in Round 2, who won on a judges' decision and went on to win the heat.