I clean my engine bay quite often like every week. Should be okay except for the undercarriage part.If u always check your engine bay and clean it, i think it'll last. the part that is neglected the most is the undercarriage area. the exhaust piping there is very hard to reach to clean it. even if send to car detailing, they don't do the undercarriage. need to go lorry wash shop.
Maybe change to stainless steel few years later.If rust will already have rust spot. Iron rust easily like brake disc. After wash or after rain already rust. so mild steel is better in this respect. If want, stainless steel won't rust.....lol
Thank you for the information.https://www.yourmechanic.com/article/what-metal-is-the-exhaust-system-made-from
I think the 'white steel' they refer to is Aluminised Steel
On my old proton saga, these type of extractors lasted for a long time.