If your attitude towards your material possessions is modeled after the way Yaakov avinu felt towards his “pachim ketanim” and it is stemming from a place that everything we have in this world is a means to serve HKB”H, then it is ok to have a ruchnius attachement and be responsible in taking care of them, and even some nostalgia.
If the attachment is “this car makes me who I am” and there isn’t a differentiation between self and car then it’s in the range of problem. The car is it and you’re you.
Since it doesn’t seem that you have a problem with attachment, then if you channel the time you put into material possessions to ultimately be a vehicle to serve Hashem sincerely then you’re on the right track.