The　existing　flow　pipes　used　in　Volkswagen　vehicles　for　PVC　coatings　are　weak　and　would　break　easily,　the　root　cause　analysis　is　undertaken　in　this　study　to　address　this　problem,　the　structure　of　these　flow　pipe　made　by　the　traditional　manufacturing　technology　is　analyzed.　We　have　designed　and　proposed　the　manufacturing　of　the　precise　flow　pipes　for　PVC　coatings　by　combining　metal　Additive　manufacturing　with　the　traditional　processes,　including　CNC　and　electric　spark.　The　design　of　the　flow　pipe　structure　is　optimized　without　compromising　the　quality　of　the　PVC　coating.　Coating　performance　has　been　pre-evaluated　using　CFD　simulation.　The　influence　of　the　selective　laser　melting　parameters　(e.g.,　placement　orientation　of　the　forming　surface,　the　wall　thickness　of　the　pipe)　on　the　fabrication　of　flow　pipes　are　investigated,　and　the　optimized　flow　pipe　showed　better　flow　rate.　The　variation　in　pressure　inside　the　pipe　when　compared　to　the　pipes　manufactured　using　traditional　techniques.　High-quality　fabrication　of　the　flow　pipes　can　be　achieved　by　setting　the　forming　surface　angle　at　over　45　degrees　when　the　pipe　wall　thickness　was　0.15　mm.　After　the　flow　pipe　fabrication　by　SLM,　the　outlet　was　processed　by　the　electric　spark　drilling　to　improve　its　surface　quality　and　coating　performance.　Tests　are　performed　to　coat　PVC　glue　on　the　lid　of　the　trunk　using　the　optimized　flow　pipe.　The　coated　PVC　glue　has　resulted　in　a　smooth　surface　with　an　appropriate　width,　qualifying　it　as　Grade　A.　The　experiments　demonstrate　the　capability　of　the　combination　of　SLM　and　traditional　manufacturing　techniques　to　fabricate　complexed　parts　with　high　precision.