germany
That question has a lot of if's and when's attached. I will simplify the question a bit: a person is in an enclosed space and another person is preventing them from getting out without any legal reason. In this case, through a physical barrier and the threat of violence to not remove it.
This is covered by
Strafgesetzbuch (StGB)
§ 239 Freiheitsberaubung
(1) Wer einen Menschen einsperrt oder auf andere Weise der Freiheit beraubt, wird mit Freiheitsstrafe bis zu fünf Jahren oder mit Geldstrafe bestraft.
Translation:
Criminal Code (StGB)
§ 239 Deprivation of liberty
(1) Anyone who imprisons or otherwise deprives a person of liberty shall be liable to a custodial sentence not exceeding five years or to a monetary penalty.
Further paragraphs clarify the sentencing. Note that there is no intention to do anything with the "prisoner" necessary. If you lock someone in, it's illegal. That seems to be your example, because your person with a bike shows no intention to do anything else than not letting them go.
Hostage taking on the other hand requires that a threat of deadly force or bodily harm is used to gain something. Your example has neither the "I want you to..." part, nor the "if not, I'm gonna hurt you" part. Nor has the offender contacted anyone else to make those demands and threats. So it doesn't qualify for a hostage situation... yet.
Emphasis mine to mark the difference to the above:
Strafgesetzbuch (StGB)
§ 239b Geiselnahme
(1) Wer einen Menschen entführt oder sich eines Menschen bemächtigt, um ihn oder einen Dritten durch die Drohung mit dem Tod oder einer schweren Körperverletzung (§ 226) des Opfers oder mit dessen Freiheitsentziehung von über einer Woche Dauer zu einer Handlung, Duldung oder Unterlassung zu nötigen, oder wer die von ihm durch eine solche Handlung geschaffene Lage eines Menschen zu einer solchen Nötigung ausnutzt, wird mit Freiheitsstrafe nicht unter fünf Jahren bestraft.
Translation:
Criminal Code (StGB)
§ 239b Hostage-taking
(1) Anyone who kidnaps a person or takes possession of a person in order to compel him or a third party to act, tolerate or refrain from an act by threatening the victim with death or serious bodily harm (§ 226) or with deprivation of his or her liberty for more than one week, or anyone who exploits the situation of a person created by him or her through such an act to carry out such coercion, shall be punished with imprisonment for not less than five years.
Since you completely changed the question mentioning that the person is free to go, they just have to leave their car in the parking lot... obviously this is neither Freiheitsberaubung nor Geiselnahme.
This would be a "Nötigung". Just like someone intentionally parked their car so you cannot get out of your parking spot, or driving too close flashing their lights so you are forced to let them pass.
Strafgesetzbuch (StGB)
§ 240 Nötigung
(1) Wer einen Menschen rechtswidrig mit Gewalt oder durch Drohung mit einem empfindlichen Übel zu einer Handlung, Duldung oder Unterlassung nötigt, wird mit Freiheitsstrafe bis zu drei Jahren oder mit Geldstrafe bestraft.
Translation:
Criminal Code (StGB)
§ Section 240 Coercion
(1) Anyone who unlawfully coerces a person into an act, acquiescence or omission by means of force or by threatening a serious evil shall be liable to a custodial sentence not exceeding three years or to a monetary penalty.