"the potency means you're still hanging onto its coat-tails"

“And while I say the 4 is plush, we’re talking in relative terms. These are still lightweight, immediately responsive cars and infinitely ‘better’ than Atom 1s. But Ariel’s strapline is ‘Serious Fun’, and as you move along the evolutionary line [from Atom 1 to Atom 4], ‘Serious’ starts to feel like it’s written in a larger font. I wonder, with the [Atom] 5, whether they will shift the dial the other way.”