Wet layups use more resin, require alot more hand labor, and tend to chip overtime due to the over saturation of fibers since the usual ratio is 27% resin to fiber based upon the weight and density. Now does that matter for trim, likely not. Ive seen the OEM CF trim with large cracks down the middle which is interesting to see from BMW however its fixable with an experience shop. Ive fixed a few myself and its not very hard but i deal with fiber daily.
Vacuum infusion is the most costly but less work overall. It requires several layers of materials to properly infuse the part with resin but removes all voids and excess via vacuum then remains under vacuum for 6-9 hours depending on the temp that day. How clean the edges are complex corners are on the rear of a part tell how skilled the shop was with wet layups. I have seen too many trim parts that look great on the front but the rear shows alot of skipped steps and uneven seams/weaves/edges that arent flush. But from the front half its not a issue. Im just a stickler for details though.
As an example of VI process; we have a few 2 stage vacuum pumps that run about $1500 and over 150ft of materials used to aide the process. Start up costs for VI arent cheap which is why most go the cheaper route for hand layups.
Longevity and clarity of the resin process is key, so wet lays tend to be clear but have small layer builds that reflect light differently at each layer height. Whereas infusion is controlled and singular in process which has a more glass/water like appearance under direct light. Its almost trippy to see. But the wow factor is there every time.
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