But this defi one I bought seems responsive enough based on the video I saw on the previous owner's car. Size 52mm hopefully not too big, matching my AEM AF meter. I try first on the A pillar, already bought a casing too for 2 meters. The thing is I don't like cables showing up too much and I want neat looking dash so pillar installation seems to be the tidiest way. Another option is to put them with stands on top of the steering column cover angled sideways so won't block the other instrument cluster but not sure if can do with just double tape coz I don't want to drill and screw it.mechanical is big and clumsy. I find anything on the A-pillar kinda blocks your view. The other day a full grown woman was hidden by the A-pillar when I was driving and I don't usually miss pretty fully grown women!