Stability on the motorway - MR2 Mk3

[Frimley111R]

SWMBO has a Mk3 MR2. Its not a bad car but does seem ‘very light’ and moves around a lot at higher motorway speeds. It’s 10 yrs old with 75k on the clock. Does this sound like a geo issue? Tyre wear seems normal.

It’s hard to assess the suspension as she hasn’t had it that long and it is generally much softer than my Elise (with higher profile tyres).