Lightmap and overlapping UV Errors, Please help!

I have a high poly, car mesh which has been provided and previously used for realistic rendering in 3ds Max and V-Ray.
I have the task of importing this car into UE4 and generating both a UE4 render and V-Ray. I managed to get a decent quality out of V-Ray but in UE4 the mesh has far too many errors for building lighting. As I haven’t created the model itself it is difficult to optimise for UE4, the mesh has a lot of polygons making it slow to work with in 3ds max and generate the best type of UV and lightmap sheet, it has multiple UV assigned to some assets and I need the same quality render that I made in V-Ray so retop is not ideal and optimising is causing crashes. I used to use ZBrush for this process in the past however do not has access to this software and stuck with how best to approach this as I have tried creating new UV sheets yet the model crashes, tried using 3D Coat with no success and tried optimising. Any help or advice would be hugely appreciated! Thanks.

Images below:

UV sheet example:


Message log:

UE4 build output:

V-Ray render and what I aim to achieve in UE4

If you want to use baked lighting in UE4 then you must have lightmap UV’s unwrapped, otherwise it will only be able to use dynamic lighting for the object which doesn’t necessarily look as good.

However, if you just want to use UE4 for rendering images, I would recommend looking into getting an Nvidia RTX graphics card, which will allow you to do raytracing renders in UE4 without having to bake lighting and use lightmaps. The current 4.22 preview version of UE4 has raytracing added

You don’t need to bake lighting on a car. Use the materials from the free automotive material pack, use the advanced lighting template in the starter content. Read up on lighting and materials, there’s been streams about rendering cars that you might want to check out.