I'm not sure. The roll bar welded in properly stiffens the chassis so I don't know if the top would make a difference or not.
I know if you want to make it handle better you should make adjustments.
Ref the SM set up guide above in the downloads or have a race shop help you if you haven't already or ask here.
There's some threads here too if you search for them.
Things don't change unless you change them.
Good luck.
J~
This week I found one of my hardtop straps snapped clean in half (B Pillar location, purchased from SafeRacer but "modified" by someone that should have known better).
There's a lot more movement there than I think we realize.
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2011 Midwestern Council Spec Miata series champion
2015 Winner, SM - Midwestern Council: A Legen-Dairy Enduro, Co-Driver Stephanie Andersen
2015 Winner, ITA - Midwestern Council, Blackhawk Formula Festival