"In this entry, I document our paint tests, failures and successes. I share my notes and recommendations on the finish options for the production units of the CSL Carbon Trunk Redux."
- Matt

Frugal where it matters.

With accessories previously test fitted, I brought the Redux trunk to the paint shop in late April to plan the paint work. 

The paint & body shop I've worked with since the redo of the E46 M3's San Marino Blue color change is highly specialized in carbon repair work, notably repairing Porsche GT and Ferrari Challenge race cars. 

They were most impressed with the quality of the carbon trunk, most notably how flat the clear coat was on the exterior shell. It prompted us to attempt an experiment: - we'd seal and apply Fire Orange paint without the use of a primer over the carbon. 

The goal was to have the thinnest layer of paint possible to ever so slightly let the carbon imprint into the paint, and most importantly to reduce labor time by using Vorsteiner's impressive craftsmanship.

As a reminder, one of the purpose of paying more upfront for quality aftermarket carbon panel is to limit expensive labor time at the paint shop.

Notes on color match. 

The trunk connects with quarter panels and rear bumper - an accurate paint match will be most important. To achieve this, I removed the fuel filler cover and brought it to the shop. 

Fire Orange has 3x different base formulations in the BASF paint system. From those 3x, we slightly modified its content to achieve a match based on the slight UV degradation of my now 13 years old M3 V8.  

Failure. 

Our test failed on 2x small sections of the trunk by the license plate and the ducktail. It's noticeable on the pictures below with the rippled, frost appearance. The culprit was the underlying clear coat; it had not fully outgassed. 

This is a relatively common occurence; the solvents in the clear take 30 to 60 days to fully evaporate from the clear coat with sun exposure. In hindsight, our odds of success were not great.

We'd have fared better had we started from a raw carbon component instead of a clear-coated unit. As this was a pre-production unit, Vorsteiner opted to deliver the trunk clear coated in and out for demonstration purposes. 

Still, we learned something along the way. We sanded down the clear and corrected the problematic sections - it all went well afterwards. 

Notes on finishes and partially exposed carbon.  

There will be 3x finishes offered for production units. 

1. Complete high gloss clear coat exterior shell and inside. 
2. Primer exterior shell and high gloss clear inside. 
3. Primer exterior shell with satin clear inside. 

If you want to re-create the signature partially exposed carbon ducktail aesthetics of yesterdays, I recommend the complete clear coated option #1. 

Your paint and body shop will have to sand down the clear on the exterior shell, and mask the outlines of the ducktail section prior to applying color coats and re-applying clear. 

The carbon's paint line. 

I chose not to do the exposed exterior paint line. Instead, the trunk's complete carbon construction would only be revealed upon opening it. The sublime clear coat work of Vorsteiner was retained, further saving paint & labor expenses. 

We masked off the interior, completely including the inner accessories section to avoid overspray from seeping and dusting onto the interior shell.  

Paint lines are rarely perfect - you'll notice some slight overspray below. This is easily removed later on without damaging the underlying paint to create a well defined edge. 

Finishing touches. 

After the paint was UV cured, the trunk was wet sanded and polished across all visible sections. The end result was a finish quality that exceeded the original paint work of the metal trunk. 

I picked up the trunk along with off-the-shelf inner taillights that were readily available. I could only source DEPO locally, this made in Taiwan variant of the original lights would do for the on-car fitment.

As you'll see below, the slight thick increase from the recent paint work did not meaningfully affect fitment. It was still perfection - off the car that is, the ultimate test is coming up next. 

This was yet another paint & body experiment that proved fruitful. 

The REDUX trunk's paint & body was less than half as much as the replica fiberglass unit.

Up next: it gets fitted to the Stripper.