library(rvest)

url <- 'https://www.otomoto.pl/osobowe/'
html <- read_html(url)

makes <- html %>%
  html_nodes("#param571 option") %>%
  html_attr('value')

remove <- c("","Marka pojazdu", "other")
makes <- setdiff(makes, remove)

for (make in makes) {
  print(make)
}