In answer to PJ I think the only reason there is cheap (often dangerous) tat for sale is there is a market for it, we are all guilty of driving prices down but are first to moan at the quality.
Yes, this has horrendous squared off rubber bumps, guaranteed to knock your tracking out.
They have removed a lot of speed bumps round here and where my mother lives they are 3 abreast in the road so all the mongs drive like they are pissed, does absolutely fa for safety.