What's the attraction?

You might be referring partly to the Niki Lauda rear wing part on ebay. I was bidding on it as it represents a terrific piece of F1 history in general and Ferrari history in particular. That crash caused Lauda nearly his life and had him pause and miss several races to come back for a storming finale and only to be beaten by Hunt in the rain of Japan, where Lauda withdrew. That withdrawal caused a riff with Enzo and ultimately led to Lauda's sacking. So that piece had a hole story attached to it (of which I only mentioned parts).

However why did I not continue to bid? None of these parts have any recognizable provenance which is everything in the art world and should be the same for pieces like these. Basically anybody can fake a part like this and pretend they picked it up after the crash. And there is a good chance that part was genuine, but there is an equal chance it was bogus.

A few years back I bought a carbon fibre nose cone from an Indycar outside the USGP. This was definitely a genuine part as it would have cost equal or more to fake it compared to what I paid (about $ 200). Besides me not being an Indycarfan, it didn't matter to me whether it was real or not. To me it is a cool looking part of a racecar and that's all that mattered.

So in short I'm with you not understanding why people would pay huge amounts for pieces of questionable provenance, but I do understand why it is cool to have some relatively unexpensive racing memorabilia at home.

PS: Several years ago I bought a spent F1 Goodyear tire as a coffe table. Was dirt cheap as well. Today you have to pay megabucks to get a similar item from eg. Exoticar.