There are several 3 wheelers available in many styles.
Choose whichever suits your eyes(style) and pocket(££££).
I have been in a Grinnal with BMW bike engine. Good fun and cost mid teens £.
3 wheelers are "different" from a car or a bike so just go with your OWN choice of style/budget. Factory built or kit.
The recall notice for he Slingshot shows the issues any manufacturer faces
the M3W has had it's share of issues and undergone( still ongoing) debate.
My own style preference for 3 wheeler is the M3W, based solely on style (££££ ignored), but if someone likes the Slingshot then fine, get what YOU prefer.
