Yes it matters. It's not just a case of the occasional spelling mistakes which may be acceptable on a quick fire discussion board, but these are the wrong words used in the wrong context. Why should the reader have to work out what the writer is trying to say because they are too lazy to correct it themselves? You have the capability of using the internet, ergo, you are seconds away from an online dictionary.
It's basic language. If you want to be understood, use the right words.
this is just a motoring forum, not a job application or a newspaper article. as long as people get the gist then I cant see a problem.
If someone uses the incorrect word e.g. their some lovely wheels you have there. then its pretty obvious what there trying to say and shouldn't require too much working out.