Enhance 3D model to be realistic and better quality

Hello, I have a 3D model which is a car parking sunshade, The model need to be improved to look better and real as it will be used for an AR application designed with UE4, the model need to be kept simple in terms of number of vertices and triangles to work smoothly on my application without issues, here are some requirements need to be fulfilled when delivering the model: 1. The model's extension is FBX. 2. 3 versions of the model need to be delivered with different dimensions as follows: a. version 1: "L5,W3,H2.5" Meters. b. version 2: "L5,W6,H2.5" Meters. c. version 3: "L5,W8,H2.5" Meters. The attached image called "Model dimensions" contains the reference of the Length, Width, and Height of the model. 3. The number of tingles and vertices of the model must be kept the same as current model. 4. The model has to look realistic with good quality and shows the small details that only appears to the user from the outside. 5. The model has to be imported in UE4 as a whole and not divided into parts. 6. The model has 3 materials slots as follows: a. Material slot for the fabric: need to provide a white textured material for the fabric along with the models. b. Material slot for the vertical and horizontal pillars and nuts. c. Material slot for the 2 diagonal supporting pillars. 7. The model must be centralized in the middle. 8. The file's size must not be more than 4 MB maximum. 9. All model's UVs has to be built and optimized correctly, the components materials also need to be designed well to make the textures and fabric look realistic, examples of bad quality results can be found in the attached images called "Bad quality fabric". Please only serious and experienced designers who are willing to fulfill these requirements must provide their offers, I am trying to build a solid and trusted base in Freelancer for future projects. Notes: 1- you can find the model in the attachments section. 2- No payments will be transferred until i test the model in my application and be fully satisfied with the result. 3- For your reference, you can find multiple images of real car parking sunshade photos for the steal and fabric in the attachments section called "Real photo".