Não lista os carros

App Module

import { BrowserModule } from '@angular/platform-browser';
import { ErrorHandler, NgModule } from '@angular/core';
import { IonicApp, IonicErrorHandler, IonicModule } from 'ionic-angular';
import { SplashScreen } from '@ionic-native/splash-screen';
import { StatusBar } from '@ionic-native/status-bar';

import { MyApp } from './app.component';
import { HomePage } from '../pages/home/home';
import { HttpClientModule } from '@angular/common/http';


@NgModule({
  declarations: [
    MyApp,
    HomePage
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    IonicModule.forRoot(MyApp)
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage
  ],
  providers: [
    StatusBar,
    SplashScreen,
    {provide: ErrorHandler, useClass: IonicErrorHandler}
  ]
})
export class AppModule {}

home.ts

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { Car } from '../../models/car'; /* importando interface TS */
import { HttpClient } from '@angular/common/http'; /* protocolo */

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  public cars: Car[];

  constructor(public navCtrl: NavController, private _http: HttpClient) {
    this._http.get<Car[]>('http://localhost:8080/api/carro/listaTodos')
    .subscribe((cars) => {
        this.cars = cars;
      }
    );
  }

}

home.htm

<ion-header>
  <ion-navbar>
    <ion-title>
      App Ionic
    </ion-title>
  </ion-navbar>
</ion-header>

<ion-content padding>
    <ion-list>
        <ion-item *ngFor="let car of cars">
          <h3>{{car.name}}</h3>
          <p>R${{car.price}}</p>
        </ion-item>
    </ion-list>
</ion-content>

Me mostra um erro:

run time error object prototype may only be an objetc or null: undefined